Preparations and Uses of Sodium Carbonate

Q. Which of the following does not decompose on heating?

1. 
2. None
3. 
4. 

Q. Which of the following compounds is consumed during the preparation of $N{a}_{2}C{O}_3$ by Solvay's process?

1. NH₃ + CaCO₃ + NaCl

2. NH₄Cl + CaO + NaCl

3. CaCO₃ + NaCl

4. NaCl + NH₄HCO₃

Q.

Sodium hydroxide or caustic soda is a useful industrial chemical and is manufactured by chlor-alkali process. In the process, a gas X is formed as the by-product. It reacts with slaked lime to give a compound Y which finds application as a bleaching agent for the clothes. How is compound Y formed from gas X? Write the chemical equation.

Q. Question 44.
For making cake, baking powder is taken. If at home your mother uses baking soda instead of baking powder in cake.

1. How will it affect the taste of the cake and why ?
2. How can baking soda be converted into baking powder ?
3. What is the role of tartaric acid added to baking soda ?

Q.

Match the salts given in column $I$with their method of preparation given in column $II$.

Column 1	Column 2
$\mathrm{Pb}{\left({\mathrm{NO}}_3\right)}_2\mathrm{from}\mathrm{PbO}$	Simple displacement
${\mathrm{MgCl}}_2\mathrm{from}\mathrm{Mg}$	Titration
${\mathrm{FeCl}}_3\mathrm{from}\mathrm{Fe}$	Neutralisation
${\mathrm{NaNO}}_3\mathrm{from}\mathrm{NaOH}$	Precipitation
${\mathrm{ZnCO}}_3\mathrm{from}{\mathrm{ZnSO}}_4$	Combustion

Q. A good method to separate alum (fitkari) from its solution is.

1. filtration
2. sublimation
3. crystallisation

Q.

Question 53
An element A reacts with water to form a compound B which is used in whitewashing. The compound B on heating forms an oxide C which on treatment with water gives back B. Identify A, B and C and give the reactions involved.

Q. A solid substance X has properties of a disinfectant due to release of chlorine gas when exposed to atmospheric carbon dioxide. Identify X.​

1. NaCl
2. $Ca\left(OC{l}_2\right)$
3. NaOCl
4. ${BaCl}_2$${.2H}_{2}O$

Q. (a) Describe how washing soda is produced starting from sodium chloride (common salt). Write equations of all the reactions involved.
(b) State whether an aqueous solution of washing soda is acidic or alkaline? Give reason for your answer.
(c) What is meant by saying that washing soda has detergent properties?
(d) Give two important uses of washing soda (or sodium carbonate).

Q. A good method to separate alum (fitkari) from its solution is.

1. filtration
2. crystallisation
3. sublimation