Answer: In a reaction between newly precipitated aluminum hydroxide and caustic soda solution, sodium meta aluminate is formed as a white salt. Al(OH)3 + NaOH → NaAlO2 {Sodium meta aluminate} +...
Solution: Copper also reacts with dil HCl and produces hydrogen and it also reacts with NaOH. (c) (iii) Zn + 2NaOH → Na2ZnO2 {Sodium zincate} (Colourless) + H2 Zn + HCl →...
Solution: When dilute HCl is added to the lead nitrate (Pb(NO3)2) solution and heated, it forms a white precipitate of lead chloride (PbCl2) and nitric acid. A double displacement reaction occurs in...
Solution: Fe + 2HCl → FeCl2 + H2 NH3 + HCl →NH4Cl FeS + 2HCl →FeCl2 + H2S MgSO3 + 2HCl → MgCl2 + H2O + SO2 NaHCO3 + HCl → NaCl + H2O + CO2
Solution: (a) (iii) An aqueous solution of copper sulfate is blue. (b) (iii) FeSO4 {Dirty green} + 2NaOH → Fe(OH)2 ↓ {gelatinous ppt.} + Na2SO4
Answer: (a) PbO- Lead Oxide (b) ZnO- Zinc Oxide (c) K2ZnO2
Solution: (a) Zinc metal salt solution was used. $ZnCl_2$(b) The formula of white gelatinous precipitate is $Zn(OH)_2$
Solution: AgNO3 + HCl → AgCl ↓+ HNO3 Mg + HCl → MgCl2 + H2 ↑ NaOH + HCl → NaCl + H2O ZnCO3 + 2HCl → ZnCl2 + H2O + CO2 ↑ CuO + 2HCl → CuCl2 + H2O
Substance Added Gas Evolved Odour Calcium Carbonate Magnesium ribbon Manganese(IV) oxide with heating Sodium sulphide Solution:
Solution: Three parts concentrated hydrochloric acid and one part concentrated nitric acid can be used together to produce nascent chlorine. 3HCl (conc) + HNO3(conc) → NOCl + 2H2O + 2...
Solution: The following are some of the applications of hydrochloric acid: Table salt is purified using this method. They're used as pH regulators and neutralizers. To clean pools, it's used as a...
Solution: Hydrogen Chloride (HCl)Gas Physical Properties It's a colourless gas.It has a sour flavour and a strong odour.It is readily soluble in non-polar solvents such as water.The melting point of...
Answer: Zinc chloride (ZnCl2) is soluble in excess of ammonium hydroxide. ZnCl2 + 2NH4OH → Zn(OH)2 ↓ {White gelatinous ppt.} + 2NH4Cl With an excess of NH4OH ppt. dissolves Zn(OH)2 + 2NH4Cl +...
? Write balanced equations for these reactions.Solution: Caustic soda is Sodium hydroxide (NaOH) (c) Pb(NO3)2 + 2NaOH → Pb(OH)2 ↓ {White ppt. (colourless)}+ 2NaNO3 In excess of alkali, the white precipitate of Pb(OH)2 becomes soluble. Pb(OH)2 +...
, (b) 
Write balanced equations for these reactions.Solution: Caustic soda is Sodium hydroxide (NaOH) (a) FeCl3 + 3NaOH → Fe(OH)3 ↓ {Reddish-brown ppt.}+ 3NaCl In excess of alkali, the reddish-brown ppt. of Fe(OH)3 remains insoluble. (b) ZnSO4 +...
Solution: (i) CuSO4 + 2NH4OH → Cu(OH)2 ↓ + (NH4)2SO4 With an excess of NH4OH, ppt. dissolves Cu(OH)2 + (NH4)2SO4 + 2NH4OH → [Cu(NH3)4]SO4 + 4H2O ii) ZnSO4 + 2NH4OH → Zn(OH)2 ↓ + (NH4)2SO4 With an...
Answer: FeCl3 + 3NH4OH → Fe(OH)3 ↓ + 3NH4Cl
Solution: NH4OH + HCl →NH4Cl + H2O. Pb(NO3)2 +HCl →PbCl2 +2HNO3. HCl + NH4OH → NH4Cl + H2O. NH3 + HCl → NH4Cl.
Solution: The following experiment can be used to demonstrate that hydrochloric acid contains both hydrogen and chlorine.Step 1: Prepare a voltameter for water electrolysis with a platinum cathode...
Solution: For 2(g): For 2(i): PbO + 2NaOH → Na2PbO2 + H2O (Yellow) Sodium Plumbate (Colourless, soluble)
Answer: (i) PbO (j) Ammonium ion
Answer: (g) Aluminium (h) Zn(OH)2 and Al(OH)3
Solution: Hydrogen chloride and ammonia react to form ammonium chloride.
Answer: (e) Na+, Ca2+ (f) Fe2+, Mn2+
Answer: (c) NaOH : A strong alkali dissociates completely to form OH- ions. (d) NH4OH: A weak alkali only partially dissociates to form OH- ions.
Answer: (a) Cu(OH)2 : Copper (II) hydroxide is amphoteric in nature and soluble in excess ammonium hydroxide. (b) ZnO: It is amphoteric which means that it dissolves in both acidic and basic...
Solution: Because the molecules of dilute hydrochloric acid HCl(g) get mixed with water vapour. A solution of HCl gas in water is known as dilute HCl. (i) The greatest concentration achieved at 20°C...
Solution: Concentrated Sulfuric acid (H2SO4) (i) Sodium chloride is treated with strong sulphuric acid to produce hydrogen chloride gas. To remove moisture, the HCl gas is delivered through a drying...
Answer: (a) Ferrous salts – Light green (b) Ammonium salts – Colourless (c) Cupric salts – Blue (d) Calcium salts – Colourless (e) Aluminium salts...
Answer: When it comes to experimental measurements, standard temperature and pressure are standard sets of circumstances that must be created in order for comparisons to be made between different...
Answer: It is described by Avogadro's law, which describes the link between the volume of a gas and the number of molecules contained inside it. It was first proposed in 1811 by an Italian physicist...
Answer: The law describes Gay-law Lussac's of combining volumes, which is a mathematical formula.It is responsible for determining the atomicity of gases.Contributes to determining a gas's molecular...
Answer The ratio of the average mass of atoms of a chemical element in a given sample to the atomic mass constant is a dimensionless physical quantity defined as the ratio of the average mass of...
Answer: Avogadro's number is equal to $6.02214076$ $\times $ $10^{23}$, which is the number of units contained in one mole of any material (defined as its molecular weight in grams).
Answer: Atomicity is defined as the total number of atoms present in a molecule. Atomicity is measured in parts per million. For example, the molecule of oxygen is made up of two oxygen atoms per...
Atomicity is defined as the total number of atoms present in a molecule. Atomicity is measured in parts per million. For example, the molecule of oxygen is made up of two oxygen atoms per molecule....
Answer: According to chemistry, the empirical formula of a chemical compound is the simplest positive integer ratio of all of the atoms that are present in the complex. As a basic illustration of...
Answer: In chemistry, the term "stoichiometry" refers to the relationship between the quantities of reactants and products present before, during, and after chemical processes. Stoichiometry is...
Answer: Gay-law Lussac's of combining volumes asserts that, when distinct gases react together, they do so in terms of volume that bears a simple whole-number ratio, given that the temperature and...
Answer: When the volume of a gas is held constant, Gay-Law Lussac asserts that the pressure of a given amount of gas varies directly with the absolute temperature of the gas. During the cooling...
Solution: Calculating the volume: Gram molecular weight of $Cl_{2}$ (one mole) $=35.5 \times 2=71 g$. $71 g$ of $Cl {2}$ at S.T.P occupies $22.4$ litres.$\therefore 7.1 kg$, i.e., $7100 g$ of $Cl...
Solution:The vapor density is defined as the mass of n molecules of gas divided by the mass of n molecules of hydrogen.The vapor density is equal to the molar mass of gas divided by the molar mass...
Solution: When the volume of a gas is held constant, Gay-law Lussac asserts that the pressure of a given amount of gas varies directly with the absolute temperature of the gas, and vice versa. From...
Answer: The weight of a certain molecule of gas (in this case, carbon dioxide) is the same as the weight of a molecule of hydrogen (22), provided that both gases are at the same temperature and...
Answer: The reason for this is that hydrogen gas is diatomic, but helium gas is monoatomic, and as a result, they are diatomic. When comparing the number of atoms in one mole of hydrogen to the...
Answer: One mole of a material (gas) occupies the volume equal to the volume filled by one mole of the substance (gas) at normal temperature and pressure. The experimental value gas at STP is 22.4...
Answer: It is stated that "equivalent volumes of all gases at the same temperature and pressure have the same number of molecules," according to Avogadro's Law. If the temperature and pressure of an...
Solution: Atomic weightGram-molecular weightMolecular formula Explanation: 1. The atomic mass is the mass of a single atom in the universe. In spite of the fact that the kilogramme is the standard...
Solution: One mole of a substance is equal to 6.022 × 10²³ units of that substance (such as atoms, molecules, or ions). The number 6.022 × 10²³ is known as Avogadro's number or Avogadro's constant....
Solution: 3. Atom This is a fact the atom is the smallest unit of matter. 4. Gases When equal volumes of different gases are mixed under the same conditions of temperature and pressure, Avogadro's...
Solution: Answer: 1. Molecule When using a relative scale, the mass of 12C (carbon twelve) is defined as 12 amu; therefore, this is an accurate number. Atomic mass is measured in amu. They tell us...
(i) The element B would have (lower /higher) metallic character than A. (ii) The element A would probably have (lesser / higher) electron affinity than B. (iii) The element A would have...
(b) An element with the atomic number 19 will most likely combine chemically with the element whose atomic number is: (i) 17 (ii) 11 (iii) 18 (iv) 20 (c) Rewrite the...
(i) Lithium (ii) Carbon (iii) Boron (iv) Fluorine (b) The metals of Group 2 from top to bottom are Be, Mg, Ca, Sr and Ba. (i) Which of these elements will form ions most...
(i) Ionisation potential increases over a period from left to right because the A. Atomic radius and nuclear charge increase B. Atomic radius and nuclear charge decrease C. Atomic radius...
A. Lithium B. Carbon C. Chlorine D. Fluorine (b) Group No.1-1A2-IIA13-IIIA14-IVA15-VA16-VIA17-VIIA18-02nd periodLiDOJNe3rd periodAMgESiHM4th periodRTIQUY In the above...
An element in Period 3 whose electronic affinity is zero. A. Neon B. Sulphur C. Sodium D. Argon (b) Give reason: (i) The ionisation potential of the element increases across a period. (ii)...
(b) Select the correct answer: (i) Across a period, the ionisation potential ………… [increases, decreases, remains the same] (ii) Down the group, electron affinity ………… [increases, decreases, remains...
(b) Electronegativity across the period ………… [increases/decreases]. (c) Non-metallic character down the group ………… [increases/decreases]. (d) Atomic number of an element is 16. State (i) to which...
A. Lithium B. Carbon C. Fluorine D. Neon (b) Group No. ’s IAIIAIIIAIVAVAVIAVIIA012131415161718LiDOJNeAMgESiHKBCFGL Select from the table: (i) Which is the most electronegative? (ii) How...
(a) Atomic size increases from left to right across a period. (b) Ionization potential increases from left to right across a period. (c) Electron affinity increases going down a group. (d)...
Li, Be, B, C, O, F, Ne (a) To which period do these elements belong? (b) One element of this period is missing. Which is the missing element and where should it be placed? (c) Place the three...
(a) The non-metallic character of the elements: (i) Decreases (ii) Increases (iii) Remains the same (iv) Depends on the period (b) The electronegativity: (i) Depends on the number of valence...
(a) The element below sodium in the same group would be expected to have a …………… (lower/higher) electro-negativity than sodium, and the element above chlorine would be expected to have a...
AlClMgNaPSSi1.531.20.92.12.51.8 Arrange the elements in the order in which they occur in the periodic table from left to right. (The group 1 element first, followed by the group 2 element and so on,...
(a) P, Na, Cl (b) F, O, Ne (c) Ne, He, Ar Explain your choice. Answers: (a) Cl has the highest ionization energy. Normally, non-metals have high ionisation energy when...
(a) Cl¯, Cl (b) Mg2+, Mg, Mg+ (c) N, O, P Answers: (a) Cl < Cl¯ (in order of increasing radii) (b) Mg2+ < Mg+ < Mg (in order of increasing radii) (c) O...
The ionization enthalpy of an element is the minimum amount of energy needed to remove the outermost electron from a gaseous neutral atom. Given, The relative position in a group: X is above the Y...
[SO2, SiO2, Al2O3, CO, MgO, Na2O] (a) A covalent oxide of a metalloid. (b) An oxide which when dissolved in water forms acid. (c) A basic oxide. (d) An amphoteric oxide. ...
(a) Which of these have physical and chemical properties resembling chlorine? (b) Which is more electronegative than chlorine? Answers: (a) The elements having the atomic number of 9 and 35 have...
(a) Mg, Cl, Na, S, Si (increasing order of atomic size) (b) Cs, Na, Li, K, Rb (increasing metallic character) (c) Na, K, Cl, S, Si (increasing ionisation potential) (d) Cl, F, Br, I...
(a) An alkali metal in period 3 and halogen in period 2 (b) The noble gas with 3 shells (c) The non-metals present in period 2 and metals in period 3. (d) The element of period 3...
Answer: (a) The answer is (B) Magnesium because magnesium can easily react with oxygen to undergo oxidation reaction forming magnesium oxide (b) The answer is (B) Magnesium oxide. Magnesium...
Answer: (a) Carbonate, calcination (b) Roasting (c) Sulfides
Aluminum, the most prevalent metal in the earth's crust, belongs to Period 3, Group IIIA of the periodic table (13)
Answer: (a) The processes involved in: (i) Dressing of ores are: Hydraulic washing Magnetic separation Froth floatation Chemical method/Leaching (ii) Refining of ores are:...
(a) The chemical names and formulae of main ores have been mentioned below: (b) Aluminum oxide makes up to 60% of the bauxite ore. Ferric oxide, sand, and titanium oxide are the other...
The significance of bauxite and sodium hydroxide in the extraction of aluminium had been mentioned below:
(a) Cryolite (b) Graphite Name of the substanceImportance in aluminium extraction(a) Cryolite It is utilized to lower fusion temperatures while also increasing conductivity.(b) Graphite Thick...
An alloy is a homogenous mixture of two or more metals or one or more metals with a few non-metallic elements Qualities of alloy differ from those of its constituents. Gold, for example, is far too...
An amalgam is a mixture or alloy of mercury with a variety of metals or a mixture of silver, gold, zinc, sodium, and non-metals. An example of amalgam is a dental amalgam made up of mercury and a...
Answer: (a) The answer is (B) Magnesium. (b) The answer is (A) Zinc oxide
It is the process of heating concentrated ores like carbonate or hydrated oxide to a high temperature in the absence of air. The mineral must be too hard to melt at this temperature. Example - Metal...
Roasting is a technique that involves heating concentrated ore to a high temperature in the presence of air. Zinc blende (ZnS) is an ore that undergoes roasting to produce its oxide, zinc oxide. The...
The froth flotation method was employed to concentrate this ore. This technique is based on the gangue particles' preference for water wettability over the ore's preference for pine oil wettability.
Answer: (a) Zinc blende is a type of zinc ore. Zinc sulfide is its chemical name, and its formula is ZnS. (b) The method used to concentrate it is the froth flotation method. (c) By heating...
When hydrogen gas is passed over heated copper oxide (CuO), a black coating present on the surface give reddish-brown colour due to reverse reaction. Consequently, Copper is produced. The redox...
Because iron and zinc are very reactive, they do not exist in their free states in nature. Their metal compounds — sulfides, oxides, and carbonates – are found in nature.
Answer: (a) Calcination and roasting are two processes for converting concentrated ore into metallic oxides. Because oxides are easier to reduce to metals, concentrated ores are transformed...
The magnetic characteristics of metal particles and gauge particles are used in this procedure. On the roller belt, which is a magnetic belt, powdered ore is inserted. As a result, the magnetic...
(a) Hydrolytic method - The fundamental criterion is the difference in ore and gangue densities. We pour the ore over a sloping, vibrating corrugated table with grooves in this approach. Water is...
Haematite ore is used to extract iron from it. Iron is extracted from iron ore in a huge container called a blast furnace. Haematite contains iron (III) oxide, Fe2O3. The oxygen must be removed from...
Answer: The metals that can be extracted from each one of the following ores are as follows: (a) Bauxite – Aluminum (b) Calamine – Zinc
Metallurgy is the branch of science concerned with extracting metals in their purest form from the ores that exist in nature.
(a) Ore - These are the minerals from which metals are commercially mined at a low cost and with minimal effort. (b) Gangue - The earthy impurities that are frequently combined with metal minerals...
Because gold is less reactive, ornaments made of gold appear new even after several years of use. This may be seen in the reactivity series, where it is positioned at the bottom. As a result, when...
Answer: (a) Halogens are the elements in Group 17 of the periodic table. Their electronic configuration is ns2 np5. (b) Aluminum is a member of the Boron family. It belongs to the 13th group...
Answer: The position of the following in the periodic table are: (a) Alkali metals: These are elements in the periodic table that belong to Group I. They are known for forming strong alkalis...
The metals listed below are a component of the following: (a) Blood pigment – iron is a component of hemoglobin (b) Plant pigment – magnesium is found in chlorophyll
a)Name the three classes in which elements are classified. (b) Which was the first metal used by man? Answer: (a) Metals, non-metals, and metalloids are the three types of elements classified....