KIIT WORLD SCHOOL
Class 10 Assignment 4- Acids, Bases and Salts
Knowledge
1. Why should water be never added dropwise to concentrated sulphuric acid?
2. What will happen to red litmus solution when it is added to bitter gourd extract? Is it acidic or basic?
3. Which will be more acidic and why?
i)
A solution with pH value of 6.0 or
ii)
A solution with pH value of 5.0.
4. What role does water play in the litmus test?
5. If soil is acidic, what compound you spread to treat the soil?
6. Which has more H+ concentration, 1 M HCl or 1 M CH3COOH?
7. Which acid is present in fatigued muscles?
8. What is the role of tartaric acid in baking powder?
9. Why should acids be handled with care?
10. An aqueous solution has a pH value of 7.0. Is this solution acidic, basic or neutral? Which has higher pH value: 1 M HCl or 1 M NaOH
solution?
11. What happens when crystals of washing soda are left open in dry air? What is this change named as? Name two industries based on
use of washing soda.
12. What is the chemical name of washing soda? Name the three chief raw materials used for making washing soda by Solvay process.
Understanding
13. Given below are some pH values of four different liquids: 7.0, 14.0, 4.0, 2.0. Which of these could that be of: a) lemon juice b)
distilled water c) 1 M NaOH solution d) tomato juice?
14. Dry ammonia gas has no action on litmus paper, but a solution of ammonia in water tirns red litmus paper blue. Why is it so?
15. Why does HCl(g) not conduct electricity when dissolved in toluene?
16. Explain monoprotic acids, diprotic acids and triprotic acids by citing examples.
Application/ Analysis
17. Seven solutions A, B, C, D, D, E, F and G have pH 1, 2, 7, 9, 11, 13 and 14 respectively.
a) Identify which of them is strongly acidic.
b) Identify which of them is neutral.
c) Identify which of them is weakly basic.
d) Which of them will turn phenolphthalein pink?
e) Identify which of them is strong base.
f) Which of them make methyl orange pink?
18. State the chemical property in each case on which the following uses of baking soda are based:
i)
As an antacid
ii)
as a constituent of baking powder.
19. pH of gastric juice lies between 1 and 3.
a) Which substance is responsible for the specific ph of gastric juice?
b) Is it acidic or basic?
c) How is this pH range helpful in digestive system?
20. Differentiate between: a) strong acid and concentrated acid
b) weak base and dilute base
21. Salivary amylase, an enzyme present in saliva helps in digestion of starch into glucose at a pH range of 6.2 to 7.6. Take 5 ml of 1%
starch solution in two test tubes A and B and pour 2 ml of saliva in each test tube. In test tube B drop 2-3 drops of dilute HCl. Wait for
10-15 minutes and then add 2-3 drops of iodine solution in each test tube. Why does the solution turn blue-black in test tube A and
not in test tube B?
Synthesis/Evaluation
22. Identify the acid and the base from which the following salts are obtained:
a) Write their molecular formula and chemical names.
b) Write balanced chemical equation for the formation of these salts.
NaNO3, K2SO4, Ca3(PO4)2, MgCO3, KBr, CuSO4
23. Identify the compound of calcium which is used for plastering of bones. With the help of chemical equation, describe how this
compound is prepared. What special precaution should be taken during the preparation of this compound?
24. “Sulphuric acid is a dibasic acid”. Write two reaction equations to justify this statement and name the reaction products in the two
cases.
25. A calcium compound which is yellowish white powder is used as a disinfectant and also in textile industry. Name the compound. Which
gas is released when it is compound is left exposed to air?