Test
Solution: (a) Buckminsterfullerene is a carbon allotrope with 60 carbon atom clusters linked together to create spherical molecules. Nothing is left behind when it burns to generate carbon dioxide...
Solution: (a) (i) CnH2n+2 (ii) CnH2n (iii) CnH2n-2 (b) Alkanes: C5H12 , C5H8 Alkenes: C2H4 , C4H8 Alkynes: C3H4 ,C5H8
Solution: (a) Catenation is the property of carbon atoms self-combining to create a lengthy chain. Catenation is a characteristic that exists between carbon and silicon. (b) Hexane has five isomers:...
Solution: (a) Hydrocarbons are the broad term for all carbon and hydrogen-based molecules. (b) In order to reach the inert gas state by sharing electrons, carbon builds compounds primarily through...
Solution: (a) Carbon has an atomic number of 6. It has a 2,4 electronic configuration. (b) Carbon can only acquire the inert gas electron configuration by sharing electrons, therefore it forms...
Solution: (k) Ethene (l) Ethyne Ethene and ethyne are chemical molecules that belong to the hydrocarbon family. Ethene is an alkene with two carbon atoms and four hydrogen atoms in its structure....
Solution: (i) Catenation (j) Alkenes
Solution: (g) Two (h) Low; covalent
Solution: (e) Alkynes. An alkyne is an unsaturated hydrocarbon with at least one triple bond between carbon and carbon. With only one triple bond and no other functional groups, the simplest acyclic...
Solution: (c) Hydrocarbons. A hydrocarbon is an organic molecule made completely of hydrogen and carbon in organic chemistry. Hydrocarbons are an example of hydrides in group 14. Hydrocarbons are...
Solution: (a) Graphite (b) Graphite Graphite, sometimes known as plumbago, is a crystalline form of the element carbon with atoms organised in a hexagonal pattern. It is the most stable form of...
Solution: (i) Isomer of hexane: 2-methyl pentane.
Solution: Isomers are substances that have the same chemical formula but differ in other ways. Structural isomers are molecules that contain the same number and type of atoms but are bound to one...
Solution: Isopentane and neopentane are the two isomers of C5H12.
Solution: Butane, sometimes known as n-butane, is a kind of alkane with the formula C4H10. At room temperature and atmospheric pressure, butane is a gas. Butane is a combustible, colourless, and...
Solution: Propyne is a kind of alkyne having the formula CH3CCH. It's one of the ingredients in MAPD gas, along with its isomer propadiene, which was once widely utilised in gas welding. Propyne,...
Solution:
Solution: Ethane.
Solution:
Solution: Methyl group: A methyl group is a methane-derived alkyl with one carbon atom linked to three hydrogen atoms — CH3. The group is frequently abbreviated Me in formulae. Many organic...
Solution: Diamond. Each carbon atom has four electrons in its outermost shell. These electrons are shared with four other carbon atoms in diamond to form extraordinarily strong chemical bonds,...
Solution: C60 is a molecule that consists of 60 carbon atoms, arranged as 12 pentagons and 20 hexagons. The name was chosen because the geodesic domes of Buckminster Fuller provided a clue that the...
Solution: Each carbon atom in graphite forms hexagonal rings with three other carbon atoms, which are held together by weak Vander Waal interactions to form layers. These layers can slide over one...
Solution: Graphite is the black substance found within a pencil. Because graphite is a good conductor of electricity, the current will flow through the electrical circuit when we utilise the...
Solution: (a) One buckminsterfullerene molecule contains 20 hexagonal carbon rings. (b) One buckminsterfullerene molecule contains 12 pentagonal carbon rings.
Solution: Apart from propane and butane 2 isomers found in LPG are- (i) n−butane: CH3-CH2-CH2-CH3 (ii) iso-butane: CH3-CH3-CH-CH3
Solution: Carbon is the element whose allotropic form is graphite. Graphite is a crystalline form of carbon that is soft. Diamonds and fullerenes are two other types ("buckyballs"). It's opaque,...
Solution: Friedrich Wohler is the scientist who debunked the 'vital force theory' for the production of organic molecules. Wöhler is well recognised for his contributions to organic chemistry,...
Solution: True. Carbon's massive molecular structure is made up of covalently bound carbon lattices. Because these connections are extremely strong, they are rigid and have high melting points. A...
Solution: The following are two characteristics of carbon that give rise to a huge number of compounds: (i) Catenation refers to a carbon atom's ability to make bonds with other carbon atoms. (ii)...
Solution: Carbon is an element with buckminsterfullerene as one of its allotropic forms. Diamond and graphite are the other allotropic forms of carbon.
Two uses of washing soda are as follows:- Used as an electrolyte.It can be used as a water softener for laundry in the home. Two uses of baking soda are as follows:- It can be used to determine the...
The neutralisation reaction occurs when an acid and a base react to produce a product of salt and water. Examples:
Because moisture can harm the plaster of Paris by slowing the setting of the plaster due to hydration, it should be stored in a moisture-proof container. The plaster will be rendered worthless as a...
(a) Why does he shift the pH of the fresh milk from 6 to slightly alkaline? (b) Why does this milk take a long time to set as curd? Answer: (a) To prevent the milk from becoming sour due to the...
The formation of lactic acid causes fresh milk to curdle. Curd contains lactic acid. Thus, due to the presence of an acid, the pH of milk is lowered.
Hydrochloric acid (HCl) is added to test tube A, while acetic acid (CH3COOH) is added to test tube B. Amount and concentration taken for both the acids are the same. In which test tube will the...
Which solution is (a) neutral? (b) Strongly alkaline? (c) Strongly acidic? (d) Weakly acidic? (e) Weakly alkaline? Answer: In increasing order of hydrogen ion concentration: pH 11(C) < pH...
Solution: Option (a) is the answer. Zinc blende (also known as zinc sulphide or ZnS) is a zinc sulphide ore. Roasting (heating in the presence of air) converts sulphide ores to metal oxides. Zinc...
Acids have an acidic behaviour due to the presence of hydrogen ions. Because hydrogen ions can only be formed in the presence of water, water is required for acids to exhibit acidic behaviour.
Solution: Option (c) is the answer. Calamine is a zinc carbonate mineral (ZnCO3, zinc carbonate). Calcination (heating in the absence of air) converts carbonate ores to metal oxides. Calamine ore...
Ionic compounds are not present in distilled water. Rainwater, on the other hand, contains far more chemicals.Carbonic acid is formed when rainwater dissolves acidic gases from the air, such as...
Two nails should be inserted into the wooden or rubber cork and placed on a beaker as shown in the illustration. Connect a bulb, a 6-volt battery, and a wire to the switch using an iron nail. Dip...
Solution: Option (b) is the answer. Pyrolusite is a manganese ore that is primarily composed of manganese dioxide.It's a black, amorphous mineral with a granular, fibrous, or columnar structure that...
Solution: Option (b) is the answer. Roasting is the term for this procedure. Heating sulphide ores in the presence of extra air converts them to oxides.
Solution: Option (c) is the answer. When silver reacts with hydrogen sulphide gas in the air, it forms a thick layer of silver sulphide (Ag2S). The creation of a silver sulphide coating on the...
Solution: Option b is the answer. Rock salt is a sodium chloride resource. The ore's compound is sodium chloride, which has the chemical formula NaCl.
Solution: Option (c) is the answer. Metals like sodium and magnesium are extremely reactive. They are obtained by electrolysis of their molten chlorides because they are difficult to reduce.
Solution: Option (c) is the answer. Galvanisation is the process of immersing iron items in molten zinc. This results in a thin zinc covering that shields the iron object against corrosion. Because...
Solution: Option (d) is the answer. Because mercury is a less reactive metal, it can only be extracted from its cinnabar ore by heating it in the presence of air.
Solution: Option (d) is the answer. Manganese metal is recovered from manganese dioxide using an aluminum-based reduction method.
(a) Dilute sulphuric acid reacts with aluminium powder. (b) Dilute hydrochloric acid reacts with iron filings. Answer: (a) Dilute sulphuric acid reacts with aluminium powder. dilute Sulphuric Acid +...
(a) Dilute sulphuric acid reacts with zinc granules. (b) Dilute hydrochloric acid reacts with magnesium ribbon. Answer: (a) Dilute sulphuric acid reacts with zinc granules: dilute sulphuric acid +...
Solution: Option (c) is the answer. Mercury alloys are utilised as amalgams with metals such as silver, copper, tin and zinc.
Solution: Option (d) is the answer. Brass is an alloy of copper and zinc. The proportion of copper and zinc can vary in quantities, resulting in brass with different mechanical and electrical...
Indigestion is caused by the stomach producing too much acid. Antacids are medicines that are used to treat dyspepsia.
If we take 20 ml of the same solution of NaOH, the amount of HCl solution (the same solution as before) required to neutralize it will be (a) 4 mL (b) 8 mL (c) 12 mL (d) 16 mL Answer: Because 10 mL...
The answer is HCl. Calcium carbonate is found in eggshells, and when it reacts with HCl, it produces CO2, which turns lime water milky.
Because litmus paper turns blue when it reacts with a basic solution, the answer is ten (p[H more than 7). As a result, the answer is 10.
The chemical equation for the reaction of Plaster of Paris and water is
Give the equation of the reaction involved. Answer: When sodium hydrocarbonate is heated, sodium carbonate is formed, and carbon dioxide gas is released.
The sodium compound that is utilised to soften hard water is sodium carbonate.
Calcium hydroxide is the material that produces bleaching powder when exposed to chlorine.
The common name of CaOCl2 is bleaching powder.
If the soil is acidic (pH below 7), quick lime (calcium oxide), slaked lime (calcium hydroxide), or chalk should be used to treat it (calcium carbonate).
Basic solutions contain H+ ions, although hydroxide ions are more prevalent in basic solutions. As a result, the presence of hydrogen ions causes the solution to become basic.
The nature of the solution is determined by the concentration of hydrogen ions. If the concentration of hydrogen ions in a solution increases, the solution becomes acidic; conversely, if the...
The pH of solution A is 6 and the pH of solution B is 8. Which solution has more hydrogen ion concentration? Which of these is acidic and which one is basic? Answer: In order to find the hydrogen...
When a base is dissolved in sodium hydroxide solution, the number of hydroxide ions increases, but it eventually reaches saturation. Even after adding more base after reaching saturation, the...
When acid is introduced to water, a certain amount of hydronium ion will be present in a certain volume of solution. When we dilute a solution, the amount of hydronium ion per volume of solution...
When diluting an acid, it is preferred that the acid be added to water rather than the water being added to the acid, because adding water to a concentrated acid releases a large amount of heat,...
Because HCl does not emit hydrogen ions, it does not exhibit acidic behavior, and the color of the litmus paper does not change when it reacts with HCl gas.
The conductivity of electricity in acid is caused by charged particles. The conductivity of electricity in acid is due to these charged particles known as ions.
The presence of the H+ ion in water determines whether a substance is acidic or non-acidic. Acids are substances that produce hydrogen ions when they dissociate with water. As some chemicals...
The gas evolved extinguishes a burning candle. Write a balanced chemical equation for the reaction if one of the compounds formed is calcium chloride. Answer: The gas developed here is CO2 since the...
Illustrate with an example. How will you test for the presence of this gas? Salt and hydrogen gas are generated when an acid combines with any metal. Metal + Acid → Salt + Hydrogen gas
Acids are found in curd and sour foods, and these acidic chemicals react with metal. This reaction turns food into poison, putting people's health at risk.
The three test tubes contain distilled water, acidic solution, and the basic solution respectively. There is only red litmus paper available in order to identify what is there in each test tube. How...
Copper is used to make hot water tanks, rather than steel (an alloy of iron) because copper does not react with either water or steam, whereas iron reacts with steam to corrode the tank.
He promised to bring back the glitter of old and dull gold ornaments. An unsuspecting lady gave a set of gold bangles to him which he dipped in a particular solution. The bangles sparkled like new...
MetalsNon-metals1. When metals are heated with oxygen, ionic oxides occur, which are basic in nature and dissolve in water to produce bases. This changes the colour of red litmus paper to blue.1....
Explain why these sour substances are effective in cleaning the vessels. Answer: Lemon or tamarind is used to clean tarnished copper vessels because the sour ingredient includes acids that dissolve...
(a) Aluminium is a highly reactive metal, yet it is used to make utensils for cooking. (b) Carbonate and sulphide ores are usually converted into oxides during the process of extraction Answer: (a)...
(a) Platinum, gold, and silver are used to make jewelry. (b) Sodium, potassium, and lithium are stored under oil. Answer: (a) Because platinum, gold, and silver are highly reactive metals, they are...
When non-metals react with oxygen, acidic or neutral oxides are formed. CO is a neutral oxide, whereas N2O5 or N2O3 is an acidic oxide.
Rust-proof paints can be applied to the surface of iron to keep it from rusting.Applying oil/grease to the surface of iron items prevents the iron surface from coming into touch with moisture-laden...
He collected the gas evolved by inverting a test tube over it, as shown in figure below. (a) What will be the action of gas on (i) dry litmus paper? (ii) moist litmus paper? (b) Write a balanced...
An impure and thick block of metal M is used as anode in the electrolytic refining process, whereas a thin strip or wire of pure metal M is used as a cathode. The electrolyte is a metal M salt...
Due to their high reactivity, zinc (Zn) and magnesium (Mg) are the two metals that will displace hydrogen from dilute acids. Because gold (Au) and silver (Ag) are less reactive, they will not be...
Amphoteric oxides are oxides that react with both acids and bases to produce salt and water. PbO and Al2O3 are two examples. Amphoteric oxides are compounds that react with acids and bases to...
(a) How could you use them to distinguish between samples of metals and non-metals? (b) Assess the usefulness of these tests in distinguishing between metals and non-metals. Answer: (a) Metals are...
(a) Zinc is costlier than tin. (b) Zinc has a higher melting point than tin. (c) Zinc is more reactive than tin. (d) Zinc is less reactive than tin. Answer: The answer is c. Because zinc is more...
This compound is also soluble in water. The element is likely to be (a) Calcium (b) Carbon (c) Silicon (d) Iron Answer: Correct answer is option (a) i.e Calcium. Calcium oxide is formed when calcium...
Applying greaseApplying paintApplying a coating of zincAll of the above Answer: Answer is (c) Applying a coat of Zinc Although adding grease and painting keeps iron from rusting, both methods cannot...
(a) NaCl solution and copper metal (b) MgCl2 solution and aluminium metal (c) FeSO4 solution and silver metal (d) AgNO3 solution and copper metal Answer: The right answer is option d,...
A homogenous blend of two or more metals, or a metal and a non-metal, is known as an alloy.
Metals that are unreactive or inert in nature do not tend to corrode easily. For example, gold and platinum. These metals are inert in nature and thus do not react and so can last longer than...
Answer: A metal with a higher reactivity can displace a metal with a lower reactivity from its oxide. The displacement reaction will occur in the following cases: magnesium is the most reactive...
Metal is extracted from its oxide via the reduction technique. Heating with carbon, for example, reduces zinc oxide to metallic zinc. Example: When lead oxide is heated with carbon, it is reduced to...
The two metals found in nature in the Ffee state are gold and platinum.
(i) Mineral (ii) Ore (iii) Gangue Answer: (i) Minerals are natural chemicals (also known as elements) found in the earth's crust. For example Alums, K2SO4.Al2(SO4)3.24H2O, etc. (ii) Ores are...
The substances that have both positive and negative charges are referred to as ionic compounds. As a result, there will be a strong attraction between them. Because breaking this force of attraction...
(i) Write the electron-dot structures for sodium and oxygen. (ii) Show the formation of Na2O and MgO by the transfer of electrons. (iii)What are the ions present in these compounds? Answer: (i)...
Write the chemical reaction that takes place. Answer: Zinc is more electro-positive (reactive) than iron. As a result, Zinc takes the place of Iron in its salt solution. Ferrous sulphate has a pale...
Write the chemical reaction when iron reacts with dilute H2SO4. Answer: When dilute HCl is introduced to a reactive metal, hydrogen gas is produced.
Solution: Option (d) is the answer. Hematite: Iron is the metal recovered from the ore hematite.Hematite mineral has iron (III) oxide (Fe2O3). It is removed with aluminium.
The results obtained have been tabulated as follows Use the table above to answer the following questions about metals A, B, C and D. Which is the most reactive metal?What would you observe if B is...
Solution: Option (a) is the answer. The impure metal is deposited in the anode mud. But the pure metal is deposited on the cathode and anode mud contains contaminants.
(i) iron with steam (ii) calcium and potassium with water Answer: (i) With the release of H2, iron reacts with steam to generate a magnetic oxide of Fe. (ii) Calcium forms calcium hydroxide and...
Solution: Option (c) is the answer. Steel is a metal and carbon-containing alloy steel (a non-metal).
Solution: Option (c) is the answer. Explanation: Iron oxide is reduced to iron by aluminium during the thermite process. This molten iron is then spilt on railways between the fractured iron to...
Option (d) is the answer. Calamine: an astringent produced from zinc carbonate or zinc oxide, commonly used in the form of lotions for the treatment or pain of the skin or of bug bites.
Sodium is a reactive metal that, if left open, will react with oxygen and ignite. To avoid reactions with oxygen, moisture, and carbon dioxide in the air, sodium metal is immersed in kerosene.
Malleable metals are those that can be pounded into sheets.Ductile metals are those that can be pulled into thin wires.
Solution: Option (d) is the answer. The high-non-reactive metals are gold (Au) and silver (Ag.). Consequently, they can not react with oxygen or any other elements in the environment in their...
(i) Is the best conductor of heat? (ii) Is a poor conductor of heat? Answer: (i) Silver is the best heat conductor. (ii) Mercury and lead are both poor heat conductors.
(i) Is a liquid at room temperature? (ii) Can be easily cut with a knife? Answer: (i) Mercury is a liquid when kept at room temperature. (ii) The metals sodium and potassium may be sliced with a...
Solution: Option (b) is the answer. Cinnabar is a hazardous HgS-containing mercury sulphide mineral. It is mercury's sole significant ore. It has a shiny red colour, which for thousands of years in...
Solution: Option (d) is the answer. Explanation: Amalgam is understood to be an alloy containing mercury. Zinc amalgam is a liquid mercury and zinc alloy.
Solution: Option (c) is the answer.
Solution: Option (b) is the answer.
Solution: Option (c) is the answer.
Solution: Option (d) is the answer.
Solution: Option (a) is the answer.
Solution: Option (c) is the answer. Because a thin oxide layer forms on the surface of aluminium, it resists corrosion (aluminium oxide or Al2O3). This inhibits additional corrosion by forming a...
Solution: Option (d) is the answer. Mercury and copper are both low on the reactivity range and are less reactive metals. As a result, they can be removed by heating their sulphides in air and then...
Solution: Option (c) is the answer. Bauxite is a reddish clay-based rock that is most often found in tropical and subtropical climates. Aluminum oxide compounds (alumina), silica, iron oxides, and...
Solution: Option (c) is the answer. Hematite, sometimes spelt haematite, is a common iron oxide compound with the formula Fe₂O₃ that may be found in a variety of rocks and soils. Hematite crystals...
Solution: (d) An alloy is a combination of two or more metals that is homogenous (or a metal and small amounts of non-metals). Alloys include metals such as steel and brass. (e) Alloys are tougher...
Solution: Option (d) is the answer. Pyrolusite is a mineral consisting essentially of manganese dioxide (MnO2) and is important as an ore of manganese. It is a black, amorphous appearing mineral,...
Solution: (a) Zinc (b) Cinnabar Mercury (II) sulphide, HgS (c) The concentrated copper (I) sulphide ore (copper glance), Cu2S is roasted in the air to oxidize copper (I) sulphide to copper (I)...
Solution: (c) Mercury (II) sulphide ore is roasted in the air to give mercury (II) oxide. 2HgO → 2Hg(l) + O2(g) (d) Anode – Thick block of impure metal M. Cathode – Thin strip of pure metal M....
Solution: (a) Sodium. (b) (i) Calamine; Zinc carbonate, ZnCO3 (ii) Zinc blende; Zinc sulphide, ZnS
Solution: (c) When zinc sulphide (zinc blende ore) is roasted in the air, zinc oxide and sulphur dioxide are formed. Roasting is the term for this procedure. 2Zn(s) + 3O2(g) → 2ZnO(s) + 2SO2 Zinc...
Solution: (a) Aluminium. (b) Haematite; Iron (III) oxide, Fe2O3.
Solution: (c) Aluminium metal is recovered from molten aluminium oxide by electrolytic reduction (electrolysis). When molten aluminium oxide is exposed to an electric current, it decomposes into...
Solution: (a) Haematite ore is used to extract iron. (b) Bauxite; Al2O3.2H2O; Aluminium oxide
Solution: (d) Electrolytic reduction of molten sodium chloride extracts sodium metal. When molten sodium chloride is exposed to an electric charge, it decomposes into sodium metal and chlorine gas....
Solution: (a) Minerals are naturally occurring metals or their compounds, whereas ores are minerals that contain a large amount of metals that may be extracted successfully. (b) Mercury. c) Sodium...
Solution: (a) Gold and platinum are mostly found in the free state in nature. (b) Sodium and Magnesium are almost always found together. (c) Iron (III) oxide; haematite ore contains...
Solution: (c) When calamine ore is calcined, carbon dioxide is produced. (d) When cinnabar ore is roasted, sulphur dioxide gas is produced.
Solution: (a) To get aluminium metal, aluminum oxide is electrolyzed in a molten condition. During the process, oxygen gas is produced. (b) To produce sodium metal, sodium chloride is electrolyzed...
Solution: A broad block of impure metal is used as an anode (attached to the battery's +ve connector) and a thin strip of pure metal is used as a cathode when electrolysis is used to refine an...
Solution: (a) In addition to carbon, aluminium can be employed as a reducing agent. (b) When sodium chloride is electrolyzed in an aqueous solution, sodium metal is produced at the cathode and...
Solution: (a) Zinc carbonate decomposes into zinc oxide and carbon dioxide when heated rapidly in the absence of air. ZnCO3(s) → ZnO(s) + CO2 (b) Copper metal and sulphur dioxide are formed when...
Solution: (a) When the paint is put to a surface, it keeps the object from rusting by preventing air and moisture from coming into touch with it. (b) Copper alloys such as brass and bronze have...
Solution: (a) Brass: It is made up of 80 per cent copper (Cu) and 20 per cent zinc (Zn). It's used to make kitchen utensils. (b) Copper reacts slowly with carbon dioxide and water to form a basic...
Solution: (a) Aluminium and zinc are corrosion-resistant metals. (b) (i) Painting. (ii) Grease or oil application. (iii) Galvanization. (iv) Plating with tin and chromium. (v) Stainless steel is...
Solution: (a) An alloy is a homogeneous mixture of metals that is made by melting the individual metals and cooling them to room temperature. (b) Steel is made up of carbon and iron. In comparison...
Solution: Rust is a red-brown flaky material that forms when an iron object is exposed to wet air (or water) for an extended period of time. This is referred to as iron rusting. We insert some...
Solution: (c) Rusting (d) When aluminium comes into proximity with wet air, it corrodes fast. It creates an oxide layer on top of the metal. It protects against rusting. Utensils are made out of...
Solution: (a) Corrosion is the result of a metal's surface being exposed to air, moisture, or a chemical. c) Platinum and gold.
Solution: A burning magnesium ribbon ignites a mixture of Iron (III) oxide and aluminium powder. With the help of a lot of heat, aluminium reduces iron oxide to produce iron metal. Iron metal is...
Solutions: (b) It is important to eliminate the gangue before extracting metal from its ore, and after that, we will get a concentrated ore. This is known as ore concentration, sometimes known as...
Solution: Solutions: (a) (i) Minerals are made up of metals or compounds found on the surface of the earth. (ii) Ores are minerals that may be used to extract metals in a practical and profitable...
Solution: Metal refining is the process of purifying impure metals. The most common technique for purifying impure metals acquired via various reduction processes is electrolytic refining. The...
Solution: Heat alone is used to recover the less reactive metals by reducing their oxides. When mercury (II) oxide is produced, for example, mercury (II) sulphide ore is roasted in the air. Mercury...
Solution: The oxides of moderately reactive metals are reduced with carbon, aluminum sodium, or calcium to extract them. Example: When zinc sulphate is heated to high temperatures in the air, zinc...
Solution: Electrolytic reduction of their molten chlorides or oxides extracts the highly reactive metals. The electrolytic reduction of molten sodium chloride, for example, extracts sodium metal....
Solution: The method of extracting metal from a concentrated ore is simply a reduction of the metal complex present. Manganese metal is made by reducing manganese oxide with aluminium powder rather...
(b) Name one ore of manganese. Which compound of manganese is present in this ore? Also, write its chemical formula. (c) A zinc ore on heating in air forms sulphur dioxide. Describe briefly any two...
Solution: (c) Calamine ore decomposes into zinc oxide and carbon dioxide when heated rapidly in the absence of air. ZnCO3 → ZnO + CO2 The zinc oxide is then heated with carbon to generate zinc...
(b) Give the name and chemical formula of one ore of copper. Solution: (a) Electrolytic reduction is the method used to extract the aluminium metal. Electrolysis is used to obtain aluminium. The...
(b) Explain why, though aluminium is more reactive than iron, yet there is less corrosion of aluminium when both are exposed to air. Solution: (a)To keep the iron grill from rusting, it is painted...
(b) What is meant by ‘anodising’? Why is it done? Solution: (a)Aluminum is more reactive than iron, and when it comes into contact with air, it creates an oxide layer, which is why it does not rust....
(b) Explain why the surface of some metals acquires a dull appearance when exposed to air for a long time. Solution: (a) Copper is used in the construction of hot water tanks because it does not...
Column IColumn IIAluminiumElectrolytic reductionZincReduction with carbonSodiumReduction with aluminiumIronManganeseTin Solution: Electrolytic reduction: Aluminium and Sodium; Reduction with carbon:...
Solution: A thermite reaction is the reduction of a metal oxide to metal utilizing aluminium powder as a reducing agent. A burning magnesium ribbon ignites a mixture of Iron (III) oxide and...
Solution: Manganese metal is extricated by the reduction of its oxide with aluminium powder as the reducing agent. In this manner, when manganese dioxide is warmed with aluminium powder, then, at...
(a) NH4NO3 (b) NH4Cl (c) CaCl2 (d) KCl Answer: Option (d) is the answer.
If the pH of the solution is less than 7, the salt is most likely to be: (a) CH3COONa (b) Na2CO3 (c) KCl (d) NH4Cl Answer: Option (d) is the answer.
(a) K2CO3 (b) K2SO4 (c) NaCl (d) NH4Cl Answer: Option (a) is the answer.
(a) CaSO3.2H2O (b) CaCl2.2H2O (c) CaCO3.2H2O (d) CaSO4.2H2O Answer: Option (d) is the answer.
(a) CaSO4 (b) Ca(OH)2 (c) Mg(OH)2 (d) KOH Answer: Option (b) is the answer.
(a) K2CO3 (b) KHCO3 (c) NaHCO3 (d) KNO3 Answer: Option (c) is the answer.
(a) KCl (b) K2SO4 (c) K2CO3 (d) KNO3 Answer: Option (c) is the answer.
(i) The alloy in which one of the metals is mercury is called an _______. (j) The electrical conductivity and melting point of an alloy is _______ than that of pure metals. (k) The rocky material...
(g) Bronze is an alloy of copper and _______. (h) The non-metal present in steel is _______. Solution: (g) tin (h) carbon
(a) Potassium sulphate (b) Sodium carbonate (c) Ammonium sulphate (d) Sodium acetate Answer: Option (a) is the answer.
(a) Potassium sulphate (b) Sodium sulphate (c) Sodium chloride (d) Potassium carbonate Answer: Option (d) is the answer.
(e) The corrosion of copper produces a _______ coating of basic copper carbonate on its surface. (f) Brass is an alloy of copper and _______. Solution: (e) green (f) zinc
(c) The process of depositing a thin layer of zinc on iron articles is called _______. (d) Tiffin boxes are electroplated with _______ but car bumpers are electroplated with _______ to protect them...
(a) Ammonium sulphate (b) Sodium acetate (c) Sodium chloride (d) Potassium carbonate Answer: Option (a) is the answer.
(a) Five (b) Two (c) Ten (d) Seven Answer: Option (c) is the answer.
(a) NaCl, Cl2 , and H2 (b) Cl2 , H2 and NaOH (c) Cl2, Na2CO3 and H2O (d) NaOH, Cl2 and HCl Answer: Option (b) is the answer.
(a) The corrosion of iron is called _______. (b) _______ and _______ are necessary for the rusting of iron. Solution: (a) rusting (b) air; water
(a) CH3COONa (b) NH4Cl (c) KCl (d) Na2CO3 Answer: Option (c) is the answer.
(a) Na2CO3 (b) Na2SO4 (c) NaCl (d)(NH4)2SO4 Answer: Option (a) is the answer.
(a) KCl (b) NH4Cl (c) Na2CO3 (d) CH3COONa Answer: Option (b) is the answer.
(a) What is meant by ‘hydrated’ and ‘anhydrous’ salts? Explain with examples. (b) Write the names, formulae, and colours of any two hydrated salts. (c) What will be the colour of litmus in an...
(a) What is salt? Give the names and formulae of any two salts. Also, name the acids and bases from which these salts may be obtained. (b) What is meant by a family of salts’? Explain with examples....
(a) What is plaster of Paris? Write the chemical formula for plaster of Paris. (b) How is plaster of Paris prepared? Write chemical equation of the reaction involved. (c) Explain why plaster of...
(a) What is bleaching powder? How is bleaching powder prepared? Write a chemical equation of the reactions involved. (b) What happens when bleaching powder reacts with dilute sulphuric acid? Give an...
(a) State whether an aqueous solution of washing soda is acidic or alkaline. Give a reason for your answer. (b) Mention two important uses of washing soda (or sodium carbonate). Answer: (a)...
(a) Describe how washing soda is produced starting from sodium chloride (common salt). Write equations of all the reactions involved. (b) What is meant by saying that washing soda has detergent...
(c) Sodium hydroxide, chlorine, and hydrogen Two uses of the above-mentioned products are as follows:- (i) Sodium hydroxide : It is used to make soap.Paper manufacturing (ii) Chlorine It is a...
(a) What happens when a concentrated solution of sodium chloride (brine) is electrolysed? Write the equation of the reaction involved. (b) Why is the electrolysis of a concentrated solution of...
(c) Which property of plaster of Paris is utilized in making casts for broken limbs in hospitals? (d) Explain why chlorine is used for sterilizing the drinking water supply. Answer: (c) Plaster of...
(a) What is the common name of the compound CaOCl2? (b) Name the raw material used for the preparation of plaster of Paris. Answer: (a) The common name of the compound CaOCl2 bleaching powder. (b)...
(a) Hydrogen (b) Hydrochloric acid. Answer: (a) Hydrogen Used as a rocket fuelUsed in oil hydrogenation (b) Hydrochloric acid Found in pharmaceuticals and cosmeticsDyeing and tanning industries for...