1. Name the acid present in ant sting _____.
A. Acetic acid
B. Citric acid
C. Oxalic acid
D. Formic acid
ANSWER:D.Formic acid
SOLUTION : Formic acid (or methanoic acid) is present in the ant sting. The chemical formula is HCOOH.
2. Which of the following salts does not contain water of crystallisation?
A. Blue vitriol
B. Baking soda
C. Washing soda
D. Gypsum
ANSWER:B.Baking soda
SOLUTION:So, baking soda does not contain water of crystallization.
3. A solution turns red litmus blue, its pH is likely to be _________
A. 1
B. 4
C. 5
D. 10
ANSWER : D.10
SOLUTION: 10 because red litmus turns blue when it comes in contact to any base and pH = 10 means base.
4. Which one of the following types of medicines is used for treating indigestion?
A. Antibiotic
B. Analgesic
C. Antacid
D. Antiseptic
ANSWER:C.Antacid
SOLUTION:Antacids are medicines used to treat indigestion. They work by neutralizing the acid in your stomach, providing relief from indigestion and heartburn. Antacids are available over-the-counter as chewable tablets or liquids
5. Acid + Metal = Salt + ____________
A. Hydrogen
B. Water
C. Carbon dioxide
D. Sulphur dioxide
ANSWER:A.Hydrogen
SOLUTION:In the above reaction, Metal (Zn) displaces hydrogen atoms from the acid (NaOH) as hydrogen gas (H2) and forms a compound called sodium zincate salt (Na2ZnO2).
6. Base + Acid = ________ + Water
A. Hydrogen
B. Salt
C. Carbon dioxide
D. Sulphur dioxide
ANSWER:B.Salt
SOLUTION:When an acid reacts with a base, the products are salt and water. This reaction is called a neutralization reaction.
7. Which gas is usually liberated when an acid reacts with a metal ?
A. Hydrogen
B. Water
C. Carbon dioxide
D. Sulphur dioxide
ANSWER:A.Hydrogen
SOLUTION :
Hydrogen gas is liberated when an acid reacts with a metal. For example, when zinc metal reacts with dil. hydrogen is evolved and salt zinc chloride is formed as: It can be tested by bringing a burning candle near the gas.
8. What is the common name of the compound CaOCl2 ?
A. Baking soda
B. Washing soda
C. Bleaching powder
D. POP
ANSWER: C.Bleaching powder
SOLUTION:Calcium hypochlorite is known as bleaching powder.
9. Name the substance which on treatment with chlorine yields bleaching powder _____.
A. Calcium oxide
B. Calcium Hydroxide
C. Chlorine
D. Sulphur dioxide
ANSWER:B.Calcium Hydroxide
SOLUTION: Therefore, Calcium hydroxide on treatment with chlorine yields bleaching powder.
10. Sodium carbonate is a basic salt because it is a salt of ________.
A. Strong acid and strong base
B. Weak acid and weak base
C. Strong acid and weak base
D. Weak acid and strong base
ANSWER: D.Weak acid and strong base
SOLUTION:
Now, we know that sodium hydroxide is a strong base and carbonic acid is a weak acid. – Therefore, sodium carbonate is a basic salt because it is a salt derived from a weak acid and strong base.