Column A Column B (a) Bleaching Powder (i) $\text{Na}_2\text{CO}_3 \cdot 10\text{H}_2\text{O}$ (b) Baking Soda (ii) $\text{CaOCl}_2$ (c) Washing Soda (iii) $\text{CaSO}_4 \cdot \frac{1}{2}\text{H}_2\text{O}$ (d) Plaster of Paris (iv) $\text{NaHCO}_3$ (e) Slaked Lime (v) $\text{Ca(OH)}_2$

V. Give One Word Answer:

Name the gas evolved when a metal reacts with an acid.
Write the formula of the functional group 'Carboxylic acid'.
Name the green coating that develops on copper articles when exposed to air.
What is the common name of the compound $\text{CaOCl}_2$?
Name the hardest substance known that is an allotrope of carbon.

SECTION B: Short Answer Type I (2 Marks each)

Why should a magnesium ribbon be cleaned before burning in air?
Define a redox reaction. Give one example.
Why does the colour of copper sulphate solution change when an iron nail is dipped in it?
Why do acids not show acidic behaviour in the absence of water?
What is the Chlor-alkali process? Write the chemical equation for it.
Why is sodium kept immersed in kerosene oil?
Differentiate between roasting and calcination.
Ionic compounds have high melting points. Why?
What are amphoteric oxides? Give two examples.
Draw the electron dot structure of (a) $\text{CH}_4$ (b) $\text{CO}_2$.
What is a homologous series? Give an example.
Why are decomposition reactions called the opposite of combination reactions?
What is observed when carbon dioxide gas is passed through lime water (a) for a short duration? (b) for a long duration?
Name two metals which are found in nature in the free state.
Define catenation. Which element exhibits this property the most?

SECTION C: Short Answer Type II (3 Marks each)

Balance the following chemical equations:
a) $\text{HNO}_3 + \text{Ca(OH)}_2 \rightarrow \text{Ca(NO}_3)_2 + \text{H}_2\text{O}$
b) $\text{NaOH} + \text{H}_2\text{SO}_4 \rightarrow \text{Na}_2\text{SO}_4 + \text{H}_2\text{O}$
c) $\text{BaCl}_2 + \text{H}_2\text{SO}_4 \rightarrow \text{BaSO}_4 + \text{HCl}$
A solution of a substance 'X' is used for whitewashing.
a) Name the substance 'X' and write its formula.
b) Write the reaction of the substance 'X' named in (a) above with water.
Write the chemical formula for (a) Washing soda, (b) Baking soda. State one major use of each.
(a) What is the pH scale?
(b) A milkman adds a very small amount of baking soda to fresh milk. Why does he shift the pH of the fresh milk from 6 to slightly alkaline?
Suggest a method to separate a mixture of Iron powder and Sulphur powder if:
a) They are just mixed physically.
b) They are heated together to form a compound.
(Explain the difference in properties).
What are alloys? Name the constituents of (a) Brass, (b) Bronze, (c) Solder.
Differentiate between metals and non-metals on the basis of their chemical properties (any three).
Explain the mechanism of the cleaning action of soaps.
Differentiate between Ethanol and Ethanoic acid on the basis of:
a) Physical state/Odour
b) Re