Question

Q7 Write Balanced Chemical Equations for the following reactions : -

(i) Dilute hydrochloric acid is added to solid Sodium Carbonate.

(ii) Sodium chloride solution is added to Lead Nitrate solution.

(iii) Barium chloride reacts with aluminium sulphate to give aluminium chloride and a precipitate of barium

sulphate.

(iv) Hydrogen + Chloride —-> Hydrogen chloride

(v) Sodium + Water —-> Sodium hydroxide + Hydrogen

Q8 2g of ferrous sulphate crystals are heated in a boiling tube. Answer the following : -

(i) Write the colour of Ferrous Sulphate crystals both before heating and after heating.

(ii) Name the gases produced during heating.

(iii) Write the chemical equation for the reaction.

Q9 The gases hydrogen & chlorine do not react with each other even if kept together for a long time. However, in

the presence of sunlight, they readily combine. What does actually happen ?

Q10 Name the salts that are used in black and white photography. Write the reactions when they are exposed to

light. Define the type of chemical reaction taking place.

Q11 (a) Write one example for each of decomposition reaction carried out with help of

(i) Electricity (ii) Heat (iii) Light

(b) Which of the following statements is correct and why ?

Copper can displace silver from the solution of silver nitrate and silver can displace copper from the

solution of copper sulphate.

Q12 a) What is difference between displacement and double displacement reactions ?

b) Why do silver chloride store in colored bottles ?

c) Draw a labelled diagram of the electrolysis of water.

Q13 (i) What is observed when a solution of potassium iodide is added to a solution of lead nitrate taken in a

test tube ?

(ii) What type of reaction is this ?

(iii) Write a balanced equation to represent the above reaction.

Q14 a) Why cannot a chemical change be normally reversed ?

b) Why is it always essential to balance a chemical equation ?

c) Write the chemical equation in the balanced form.

Fe(s) + H2O(g) ———–> Fe3O4(s) + H2(g)​

Answer 1

Answer:

Q7)1. HCl+ NaCO3 - HCO3 + NaCl

2. CaCO3 + H2O - Ca(OH)2

3. 3BaCl2+Al2(SO4)3-2AlCl3+3BaSO4

4. H2+Cl2-->2HCL

5.2Na+2H2O→2NaOH+H2.

Explanation: