chemistry MCQs - 9th class Chapter 07 Mcqs

1

What taste is characteristic of acids like lemon and lime?

A

Sweet

B

Salty

C

Sour

D

Bitter

2

According to the Arrhenius concept, what does a base produce when dissolved in water?

A

H+ ions

B

OH- ions

C

H2O molecules

D

Salt crystals

3

Which of the following is a mineral acid?

A

Acetic acid

B

Formic acid

C

Sulphuric acid

D

Tartaric acid

4

In the Bronsted-Lowry definition, an acid is a substance that...

A

accepts a proton

B

donates a proton

C

accepts an electron

D

donates an electron

5

What are water-soluble bases commonly called?

A

Alkalis

B

Amphoterics

C

Salts

D

Oxides

6

Which acid is found in tamarind?

A

Acetic acid

B

Lactic acid

C

Citric acid

D

Tartaric acid

7

The reaction between an acid and a base to form salt and water is called?

A

Dissociation

B

Ionization

C

Neutralization

D

Oxidation

8

According to the text, a strong acid is one that...

A

partially dissociates in water

B

completely dissociates in water

C

does not dissociate in water

D

only reacts with metals

9

What is the chemical formula for oxalic acid mentioned in the 'Interesting Information' box?

A

H2C2O4

B

CH3COOH

C

H2SO4

D

HCl

10

Which of the following is considered a weak base because it only partially ionizes in water?

A

NaOH

B

KOH

C

NH4OH

D

Ca(OH)2

11

In the reaction of ammonia (NH3) with water, water acts as a(n)...

A

Bronsted-Lowry base

B

spectator ion

C

Bronsted-Lowry acid

D

neutral substance

12

A compound that can act as both an acid and a base, like water, is called?

A

Neutral

B

Isotopic

C

Amphoteric

D

Ionic

13

When an acid reacts with a reactive metal like Magnesium (Mg), what gas is evolved?

A

CO2

B

O2

C

NH3

D

H2

14

What is the pH of rain water for it to be considered acid rain?

A

Greater than 7.0

B

Equal to 7.0

C

Less than 5.6

D

Greater than 5.6

15

Which gas is produced when an acid reacts with a metal carbonate like CaCO3?

A

Hydrogen

B

Ammonia

C

Sulphur dioxide

D

Carbon dioxide

16

What does a Bronsted-Lowry base do in a chemical reaction?

A

Donates a proton

B

Accepts a proton

C

Loses an electron

D

Gains an electron

17

Hydrochloric acid (HCl) present in the stomach helps to...

A

produce vitamins

B

digest food

C

neutralize alkalis

D

absorb water

18

Which of the following is an example of an Arrhenius acid?

A

NH3

B

HCN

C

Na2CO3

D

OH-

19

What is the conjugate acid of NH3?

A

H2O

B

OH-

C

NH4+

D

NH2-

20

Acid rain primarily damages structures made of...

A

wood and plastic

B

glass and rubber

C

stone and metal

D

fabric and paper

21

What is the natural source of formic acid according to Table 7.1?

A

Vinegar

B

Ant sting

C

Tomato

D

Lemon

22

A substance that feels slippery to the touch is most likely a(n)...

A

Acid

B

Base

C

Salt

D

Metal

23

Which of the following acids is diprotic, meaning it can donate two protons?

A

HCl

B

HNO3

C

H2SO4

D

CH3COOH

24

According to the text, what percentage of acetic acid molecules dissociate in solution?

A

100%

B

50%

C

1.32%

D

0.132%

25

Antacids like calcium hydroxide are used to neutralize excess...

A

base in the stomach

B

acid in the stomach

C

salt in the blood

D

water in the cells

26

In the reverse reaction of NH3 + H2O, which species acts as the conjugate acid?

A

OH-

B

H2O

C

NH3

D

NH4+

27

Which metals are mentioned as being unreactive with acids?

A

Mg, Zn

B

Na, K

C

Cu, Ag, Au, Pt

D

Fe, Al

28

When alkalis react with ammonium salts, what gas is liberated?

A

Hydrogen

B

Oxygen

C

Ammonia

D

Carbon dioxide

29

Which atmospheric gas, when mixed with moisture, forms sulphuric acid (H2SO4)?

A

NO2

B

CO2

C

SO3

D

O3

30

What is the conjugate base of the acid HCN?

A

H3O+

B

OH-

C

H2CN+

D

CN-

31

Which of the following is NOT an Arrhenius base?

A

NaOH

B

KOH

C

NH3

D

Ba(OH)2

32

Sour milk and curd contain which organic acid?

A

Citric acid

B

Lactic acid

C

Acetic acid

D

Oxalic acid

33

Aqueous solutions of acids are recognized to contain which ions?

A

OH-

B

Na+

C

H+

D

Cl-

34

Which substance is described as a strong base that ionizes completely in water?

A

Ammonium hydroxide

B

Aluminum hydroxide

C

Sodium hydroxide

D

Formic acid

35

What is the physical state of HCl when it reacts with liquid water to form hydronium ions?

A

Solid

B

Liquid

C

Gas

D

Plasma

36

What is the ion H3O+ called?

A

Hydroxide ion

B

Hydroxyl ion

C

Hydronium ion

D

Proton ion

37

According to Arrhenius, what happens to strong acids and bases when dissolved in water?

A

They remain as molecules

B

They partially dissociate

C

They evaporate quickly

D

They completely dissociate

38

The taste of bases is described as...

A

Sour

B

Sweet

C

Salty

D

Bitter

39

What is the source of ascorbic acid listed in the table?

A

Tomato

B

Tamarind

C

Amla, Guava

D

Sour milk

40

In the reaction between 2HNO3 and CaO, what are the products?

A

Ca(NO3)2 and H2O

B

CaN2 and H2O

C

Ca(OH)2 and NO2

D

CaO2 and H2O

41

Which of the following is a property of alkalis?

A

React with carbonates to form CO2

B

React with ammonium salts to liberate NH3

C

Turn red litmus blue

D

Both B and C

42

The Arrhenius concept is limited because it requires the presence of...

A

a metal

B

a non-metal

C

water as a solvent

D

high temperature

43

In the reaction HCl + H2O -> H3O+ + Cl-, which species is the Bronsted-Lowry base?

A

HCl

B

H2O

C

H3O+

D

Cl-

44

How many hydroxide ions does one formula unit of Ba(OH)2 contain?

A

1

B

2

C

3

D

4

45

What type of oxide is Na2O, which reacts with water to produce hydroxide ions?

A

Acidic oxide

B

Neutral oxide

C

Basic oxide

D

Amphoteric oxide

46

Which compound is formed when SO3 gas dissolves in water?

A

H2SO3

B

H2S

C

H2SO4

D

SO2

47

The definition 'an acid is a proton donor' belongs to which concept?

A

Arrhenius

B

Lewis

C

Bronsted-Lowry

D

Dalton

48

A weak acid like formic acid has a...

A

high degree of ionization

B

very limited extent of ionization

C

complete ionization

D

zero ionization

49

Which of the following is NOT a characteristic property of acids?

A

Sour taste

B

React with bases to form salt and water

C

Turn red litmus paper blue

D

React with reactive metals to produce H2

50

What happens to the nutrients in soil due to acid rain?

A

They become more concentrated

B

They are converted to sugar

C

They are dissolved and washed away

D

They become inert