1. Write down the chemical equations representing the formation of Salt from an acid and a base.
Ans:-
Hydrochloric acid reacts with Sodium Hydroxide to form sodium chloride and water.
NaOh + HCL --->Nacl + H2O
2. Give one example each of normal salt and an acid salt.
Ans:-
NaHco3 is an acid salt and Cu(OH)2cuco3 is a normal salt.
3. Write chemical equation describing the reaction between :-
(A) Carbonic acid and Sodium hydroxide
(B) Calcium carbonate and dilute hydrochloric acid.
(C) Magnesium hydroxide and dilute sulfuric acid.
Ans:-
A) H2CO3 + NaOH ---> Na2CO3 + H2O
(Carbonic acid + Sodium Hydroxide --->Sodium Carbonate + Water)
B) CaCo3 + HCL(aq) ---> Cacl2 + H2O +Co2
( Calcium Carbonate + Dilute hydrochloric acid ---> Calcium chloride + Water + Carbon dioxide. )
C) Mg(OH)2 + H2So4(aq) ---> MgSo4 + 2H2O
( Magnesium hydroxide +Dilute Sulphuric acid ---> Magnesium Sulphate + Water)
4. Name two salts that contain water of crystallization. Write down the formula also.
Ans:-
1. Copper sulphate - CuSo4.
2. Washing Soda / Sodium Carbonate - Na2CO3.
5. Why is the solution of sodium carbonate basic in character?
Ans:-
The solution of sodium carbonate ( Na2Co3) is basic because it contains the mixture of weak acid and strong base. They combine to form an NaOh + H2Co3 which is a mixture of are week acid and strong base.
6. Mention one use each of the following:-
A. Sodium Hydrogencarbonate
B. Sodium Carbonate
C. Copper Sulphate
Ans:-
A. It is used as an antacid, in baking powder, drying agent and in toothpaste it is also used as a fire retardant, pest control and in fireworks.
B. It is used as water softner and pH modifier.
C. It is used as a fungus side, root killer, herbicides in both agriculture and non agricultural settings.
7. Name a Calcium compound which hardens on wetting with water.
Ans:-
Plaster of paris, if a Calcium compound which hardens on wetting with water its formula is CaSo4 1/2 H2O.
8. Which of the following salt has blue colour and why?
a) CuSo4.5H2O
b) CuSo4
Ans:-
(a) CuSo4.5H2O
It has a blue colour due to the presence of water of crystallization.
9. Name three salts made from common salt.
Ans:-
1. Sodium hydroxide
2. Sodium Carbonate
3. Sodium Hydrogencarbonate
10. (A) What is baking soda? What is its chemical name ?
(B) Write the formula and two uses of baking soda
Ans:-.
A) Baking soda is a salt composed of a sodium cation and a Bio carbonate anion.
Sodium hydrogen carbonate is chemical name of baking soda.
B) Formula - NaHCo3
Uses:-
1. Reduces the acidity in stomach.
2. Acts as a pesticides.
11. How are salts classified? Give one example of each.
Ans:-
Salts can be classified in a variety of ways:-
1.Salts that produce Hydroxide ions when dissolved in water called alkali salt. For example Sodium hydroxide ( NaOH).
2. Salts that produce acidic solution are acidic salts. For example: Zinc Chloride ( Zncl2).
3. Neutral salts are those salts that are neither acidic nor basic. For example Potassium Chloride ( KCL).
12. What is meant by Water of crystallization?
Ans:-
Water of crystallization means water molecules that are present inside crystal. Water is often incorporated in the formation of Crystal from aqueous solution.
13. Name and write formula of two hydrated salts.
Ans.:-
1. Copper sulphate pentahydrate - CuSo4.5H2O.
2. Ferrous sulphate - FeSo4.7H2O.
14. What happens when copper sulphate crystal are heated strongly? Write the chemical equation.
Ans:-
On strong heating blue copper sulphate turns white they also lose water of crystallization.
(heat)
CuSo4.5H2o ‐----------> CuSo4 + 5H2o.
15. Name the raw material used in manufacturing of bleaching powder. Mention two major uses of bleaching powder.
Ans:-
Chlorine gas and dry slaked lime is used to
produce bleaching powder.
Uses:-
1.Bleaching dirty clothes in laundry.
2. It is used as a disinfectant for disinfecting water.
16. Name 2 salts and
(A) Write their formula
(B) Name the acids and bases from which these salts are obtained.
Ans:-
The 2 Salts are :-
1.Sodium Chloride
2.Ammonium Chloride
(A) Formula:-
1.Sodium Chloride :- NaCl
2.Ammonium Chlorid :- NH4Cl
(B)
* Sodium Chloride obtained from Hydrochloric acid and Sodium hydroxide.
* Ammonium Chloride obtained from Hydrochloric acid and Ammonia.
17. What is meant by the family of salts? Illustrate by giving example.
ANS.:-
If two salts have same positive (basic radicals) and negative radicals (acidic radicals) then they are called to be of same family.
For example:- NaCl and Kcl Belong to the family of chloride salts.
18. Consider the following list of chemical compounds, and answer the following:-
A) Which of two are used for preparing ammonium chloride?
B) Which compound is the part of baking powder?
C) Which compound is used as an antacid?
D) Which four compounds are used for manufacturing sodium carbonate?
(NH3, NaCl, H2o ,Cl2,Ca(OH)2, Co2, CaSo4.2H2o,NaHCo3)
Ans.:-
A) NH3, NaHCo3
B) NaHCo3
C) Ca(OH)3
D) NaCl, Co2, H2o, NH3
19. A person found that the cake prepared is hard and small in size. Name the ingredient missed during preparation.
Ans:-
He missed to add Baking powder which makes it hard and small in size, if he will add baking powder in it the cake will be soft and big in size.
20. A salt X when dissolved in distilled water gives a clear solution which turns red litmus to Blue. Explain the phenomenon.
Ans.:-
Salt X is like a sodium carbonate, Na2Co3 which is made from a strong base and weak acid. On dissolving in water, salt X get hydrolysed to some strong base and some weak acid strong base thus formed makes solution alkaline which turns red litmus to Blue.