Chemistry

Which of the following methods, A, B, C, D or E is generally used for preparing the chlorides listed below from (i) to (v). Answer by writing down the chloride and the letter pertaining to the corresponding method. Each letter is to be used only once.

A Action of an acid on a metal B Action of acid on an oxide or carbonate C Direct combination D Neutralisation of alkali by an acid E Precipitation (double decomposition) (i) Copper...

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You have been provided with three test tubes. One of them contains distilled water and the other two have an acidic solution and a basic solution respectively. If you are given red litmus paper, how will you identify the contents of each test tube?

We know that the bases turn red litmus into blue. Therefore, when a drop is placed in each test tube on a red litmus paper that turns blue can easily be seen as a base. After that, the remaining...

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M2O is the oxide of metal “M” which is above hydrogen in the activity series. M2O, when dissolved in water, forms the corresponding hydroxide which is a good conductor of electricity.
a. State the reaction taking place at the cathode.
b. Name the product at the anode.

Solution: Answer: i)M+ + 1e– → M ii) Oxygen gas is produced at the anode. Explanation: i) The activity series gives us a metal oxide M2O of metal ‘M'. M2O dissolves in water to generate hydroxide...

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Give reasons why:
a. Sodium chloride conducts electricity only infused or aqueous solution state.
b. In the electroplating of an article with silver, the electrolyte sodium Argento cyanide solution is preferred over the silver nitrate solution.

Solution: a) In the solid-state, the electrostatic forces of attraction between molecules are extremely strong, attracting molecules to one another. In the fused state, these forces grow weaker, and...

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State your observation for the following reactions. 1.Dilute HCl is added to sodium carbonate crystals. 2.Copper sulphide is treated with dilute hydrochloric acid. 3.A few drops of dil. HCl is added to silver nitrate solution, followed by addition of NH4OH solution.

Solution:  Sodium chloride is created when sodium carbonate crystals are added to liquid HCl, along with water and carbon dioxide gas. A brisk effervescence develops. The neutralisation reaction is...

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Element X is a metal with valency 2. Element Y is a non-metal with valency 3.
1. Write equations to show how X and Y form ions.
2. If Y is a diatomic gas, write an equation for the direct combination of X and Y to form a compound.
If the compound formed between X and Y is melted and an electric current is passed through the molten compound, element X will be obtained at the ________ and Y at the ________ of the electrolytic cell.

Solution: X → X2+ + 2e– ; Y + 3e– → Y3-Y2 + 3X → X3 Y2Cathode, anode

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Give reasons for the following: g) Ammonia is unionized in the gaseous state but in the aqueous solution, it is a weak electrolyte.
h) A graphite anode is preferred to other inert electrodes during electrolysis of fused lead bromide.

Answer: g) Because ammonia is a covalent molecule, it is unionized in the gaseous state, but it produces $NH_4OH$ in an aqueous solution, which can dissociate into ions when exposed to water. h)...

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Give reasons for the following:
c) Lead bromide undergoes electrolytic dissociation in the molten state, but it is a non-electrolyte in the solid state.
d) Aluminium is extracted from its oxide by electrolytic reduction and not by conventional reducing agents.

Answer: c) During the melting process of lead bromide, the ions are free and loosely packed. It is because of the electrostatic force of attraction that the ions are closely packed in the...

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Give reasons for the following:
a) Electrolysis of molten lead bromide is a reaction in which oxidation and reduction go side by side, i.e., a redox reaction.
b) The blue color of aqueous copper sulfate fades when it is electrolyzed using platinum electrodes.

Solution: a) Bromine loses electrons at the anode of lead bromide electrolysis, while lead gets electrons at the cathode of lead bromide electrolysis. As a result, it is classified as a redox...

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Distinguish by adding: sodium hydroxide solution and ammonium hydroxide solution to
(a) Calcium salt solution and lead salt solution
(b) Lead nitrate solution and zinc nitrate solution

Solution: a) The interaction of sodium hydroxide and ammonium hydroxide with calcium salt produces a milky white precipitate Ca(OH)2, whereas the reaction of sodium hydroxide and ammonium hydroxide...

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Distinguish by adding: sodium hydroxide solution and ammonium hydroxide solution to
(c) Copper salt solution and ferrous salt solution
(d) Fe(II) salt solution and Fe(III) salt solution

Solution: (c) The combination of sodium hydroxide and ammonium hydroxide with copper salt produces a pale blue-colored precipitate, whereas the reaction with ferrous salt solution produces a dirty...

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