Blog Log in Get Started Free

Chemistry MCQs for NEET — Practice Questions with Answers

Practice free Chemistry NEET multiple-choice questions online with instant answers and detailed explanations. No login required.

All Physics Chemistry Botany Zoology

Chapter Language Difficulty Show only questions I answered incorrectly Register free to filter questions

● ● ● ● ●

Ozone is prepared by passing silent electric discharge through oxygen. In this reaction [AFMC 1998]

Energy is given out

Energy is absorbed

Oxygen is loaded with energy

Oxygen is dissociated into atoms

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

$3 O_{2} ⇌ 2 O_{3}$ – energy is given out.

● ● ● ● ●

Combustion of glucose takes place according to the equation, $C_{6} H_{12} O_{6} + 6 O_{2} \to 6 C O_{2} + 6 H_{2} O$ , $Δ H = - 72 k c a l$ . How much energy will be required for the production of 1.6 g of glucose (Molecular mass of glucose = 180 g) [AFMC 1999]

0.064 kcal

0.64 kcal

6.4 kcal

64 kcal

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

$Δ H p e r 1 .6 g = \frac{72 \times 1 .6}{180} = 0 .64 k c a l$ .

● ● ● ● ●

Which of the following compounds will absorb the maximum quantity of heat when dissolved in the same amount of water ? The heats of solution of these compounds at 25°C in kJ/mole of each solute is given in brackets [AMU (Engg.) 2000]

$H N O_{3} (Δ H = - 33)$

$K C l (Δ H = + 17 .64)$

$N H_{4} N O_{3} (Δ H = + 25 .5)$

$H C l (Δ H = - 74 .1)$

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

More +ve is ΔH_s more is heat of solution.

● ● ● ● ●

A system is changed from state A to state B by one path and from B to A another path. If E₁ and E₂ are the corresponding changes in internal energy, then [Pb. PMT 2001]

$E_{1} + E_{2} = - v e$

$E_{1} + E_{2} = + v e$

$E_{1} + E_{2} = 0$

None of these

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

ΔE = 0 for a cyclic process.

● ● ● ● ●

If (i) $C + O_{2} \to C O_{2}$ , (ii) $C + 1 / 2 O_{2} \to C O$ , (iii) $C O + 1 / 2 O_{2} \to C O_{2}$ , the heats of reaction are Q, –12, –10 respectively. Then Q = [Orissa JEE 2004]

– 2

– 22

– 16

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

$C + O_{2} \to C O_{2}$ ; ΔH = q

$C + 1 / 2 O_{2} \to C O$ ; ΔH = –12 …..(i)

$C O + 1 / 2 O_{2} \to C O_{2}$ ; ΔH = –10 …..(ii)

adding equation (i) and (ii) we can get

ΔH = –12 + (–10) = –22

● ● ● ● ●

Adsorption of gases on solid surface is generally exothermic because [IIT JEE (Screening) 2004]

Enthalpy is positive

Entropy decreases

Entropy increases

Free energy increase

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

Due to randomness of particles is reduced since entropy decreases.

● ● ● ● ●

Two mole of an ideal gas is expanded isothermally and reversibly from 1 litre ot 10 litre at 300 K. The enthalpy change (in kJ) for the process is [IIT JEE (Screening) 2004]

11.4 kJ

–11.4 kJ

0 kJ

4.8 kJ

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

ΔH = nCp ΔT

The process is isothermal therefore

ΔG = 0; ∴ ΔH = 0

● ● ● ● ●

When a gas undergoes adiabatic expansion, it gets cooled due to

Loss of kinetic energy

Fall in temperature

Decrease in velocity

Energy increase during doing work

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

Due to fall in temperature.

● ● ● ● ●

In an isobaric process, the ratio of heat supplied to the system (dQ) and work done by the system (dW) for diatomic gas is [AFMC 2002]

1 : 1

7 : 2

7 : 5

5 : 7

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

$- \frac{d Q}{d W} = \frac{d Q}{d Q - d E}$ ; $d E = d W + d Q$ ; –dW = dQ – dE

$= \frac{n c_{p} d T}{n c_{p} d T - n c_{v} d T} = \frac{c_{p}}{(c_{p} - c_{v})}$

$= \frac{7 R}{2 R}$ {for diatomic of gas $c_{p} = \frac{7 R}{2}$ }

● ● ● ● ●

A Beckmann thermometer is used to measure

High temperature

Low temperature

Normal temperature

All temperature

You've reached today's free limit of 20 questions. Log in to keep practising for free.

Explanation

Backmann thermometer is used to measure low temperature.

The Beckmann differential thermometer is used for measuring small differences in temperature, having readability of around 0.001°C. This makes it useful for the determination of melting points, boiling points and calorimetry. Today it is superseded by sensitive digital thermometers using thermocouples, thermistors.

Ready to ace NEET?

Free access · No credit card required

Browse All Questions Create Free Account

Frequently Asked Questions

Yes. You can attempt every Chemistry question on this page for free without logging in, and check the correct answer with a detailed explanation instantly.

No account is required to attempt questions and view answers. A free account adds bookmarks, personal notes, and progress tracking.

The bank mixes NEET previous year questions (PYQs) with practice questions, each tagged with its exam appearances where applicable.