1.Sodium carbonate is a basic salt because it is a salt of
(a) weak acid and weak base
(b) strong acid and weak base
(c) weak acid and strong base
Answer: (c) weak acid and strong base.
Explation= Sodium carbonate is a basic salt which is formed by the combination of sodium hydroxide and carbonic acid.
Sodium hydroxide is a strong base, while cabonic acid is a weak acid resulting in the formation of sodium carbonate salt.
2NaOH+H2CO3→Na2CO3+2H2O
- Which gas is evolved when acids react with metals?
(a) O2
(b) CO2
(c) H2
(d) N2
Answer: (c) H2
Metals readily react with acid and produce hydrogen gas which burns with a pop sound. - Dilute acid does not produce carbon dioxide on being treated with: a. Marble
b. Lime
c. Baking soda
d. Limestone
Answer. b. Lime
In the given options, marble, limestone, and baking soda are all either metal carbonates or bicarbonates. All these when react with a dilute acid then they produce carbon dioxide. Whereas lime which is calcium oxide when react with a dilute acid then they do not produce carbon dioxide. - Which of the following salt will give acidic solution when dissolved in water?
a. NH4Cl
b. NaCl
c. Na2CO3
d. CH3COONa
Answer. a. NH4Cl
NaCl is a neutral salt hence, it will give a neutral solution. NH4Cl is an acidic salt hence, it will give an acidic solution. CH3COONa is a basic salt hence, it will give a basic solution. - Bleaching powder is used as a disinfectant for water to: a. Make water tastier
b. Remove all the dirt from water
c. Make water germ-free
d. Make water clear
Answer. Make water germ-free
Bleaching powder, CaOCl2 is used to kill germs and bacteria of water because it is a good disinfecting agent
- Which one of the following salts will dissolve in water to form an alkaline solution?
a. Potassium carbonate
b. Sodium chloride
c. Sodium carbonate
d. Potassium sulphate
Answer. a. Potassium carbonate
Potassium carbonate will dissolve in water to give alkaline
solution. This is because they are formed by strong base and weak acid and thus are basic in nature - Which among the following represents the chemical formula for ‘Plaster of Paris’?
Explanition= The chemical formula for the plaster of Paris is (CaSO4) H2O and is better known as calcium sulfate hemihydrate.
- The nature of calcium phosphate is present in tooth enamel is
(a) Basic
(b) Amphoteric
(c) Acidic
(d) NeutralRead
ANSWER .Basic
Calcium phosphate is a family of substances and minerals which consist of calcium ions ( Ca2 + Ca2 + ) with inorganic phosphate anions. In some calcium phosphates, oxides and hydroxides are also present. They are white solids of nutritious value. Calcium phosphates are found in many living organisms.
Calcium phosphate is basic salt since it is a source of weak phosphoric acid and a slightly stronger base of calcium hydroxide. Calcium phosphate is a mineral comprising calcium ion and phosphate ion which is inorganic in nature. It is present in the crown area of the tooth and also in bones.
Although calcium phosphate is a very hard substance, it can be dissolved in acids. Hence, we can state that the nature of calcium phosphate is basic and hence, the correct option is option (A). - Which one of the following is acidic?
(a) Lemon juice
(b) Tomatoes
(c) Milk
(d) All
Answer . All - Acids react with metals to liberate _________gas
(a) Carbon dioxide
(b) Carbon monoxide
(c) Hydrogen
(d) Water
Answer . Hydrogen
Explation= acid reacts with metal, hydrogen gas is released. - . Generally, when certain metals react with an acid they release _ gas.
A. Nitrogen
B. Oxygen
C. Hydrogen
D. Argon
Answer. Hydrogen - Which one of the given is commonly known as blue vitriol and is used as a fungicide?
A. Potassium nitrate
B. Copper sulphate
C. Sodium carbonate
D. Sodium chloride
Answer Copper sulphate
Copper(II) sulfate, also known as cupric sulfate, or copper sulphate, is the inorganic compound with the chemical formula CuSO4(H2O)x, where x can range from 0 to 5. The pentahydrate (x = 5) is the most common form. Older names for this compound include blue vitriol, bluestone, the vitriol of copper, and Roman vitriol.
- Vinegar is used in pickling as it
A. Is an acid
B. Prevents the growth of microbes
C. Prevents drying of a pickle
D. Increases taste
Answer= Prevents the growth of microbes
- PH scale of a neutral solution is
A. 14
B. 7
C. 10
D. 12
Answer. 7
The pH scale ranges from 0 to 14. A pH of 7 is neutral. A pH less than 7 is acidic. - Butyric acid is found in
A. Rancid butter
B. Rancid cake
C. Stings of bees
D. All of these
Answer. Rancid cake - An indicator is one kind of the following compound
A. Strong acid only
B. Reducing agent
C. Weak base or acid only
D. Complex salt
Answer= Weak base or acid only
indicators are chemical based compounds used to identify the acidity/alkalinity of a given compound so they should be a very weak acid /base
Important Link
Quick Revision Notes :Chapter 2 Acids, Bases, and Salts
NCERT Solution : Chapter 2 Acids, Bases, and Salts
MCQs: Chapter 2 Acids, Bases, and Salts
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