Explore topic-wise MCQs in Chemistry.

This section includes 265 Mcqs, each offering curated multiple-choice questions to sharpen your Chemistry knowledge and support exam preparation. Choose a topic below to get started.

151.

According to collision theory, increase in temperature increases

A. kinetic energy of reactants
B. heat energy of reactants
C. both a and b
D. humidity in the air
Answer» D. humidity in the air
152.

Flour mills and coal mines need to be well ventilated because

A. the surface area of coal and flour needs to be digged out
B. coal and flour particles are scattered in the form of lumps
C. coal and flour particles are scattered in the form of powder
D. coal and flour particles can get ignited very easily
Answer» E.
153.

Uses of enzymes does not include

A. production of insulin
B. production of cancer drugs
C. drug to combat plague
D. drug to fight dwarfism
Answer» D. drug to fight dwarfism
154.

Biological catalyst to convert Hydrogen Peroxide (H₂O₂) into water (H₂O) and oxygen (O₂) is

A. amylase
B. hydrolase
C. catalase
D. protease
Answer» D. protease
155.

If heated Mg(s) is allowed to react with H₂O(l), the product formed other than H₂(g) will be

A. MgO(s)
B. MgO(aq)
C. Mg(OH)₂ (aq)
D. Mg₂O₃(s)
Answer» B. MgO(aq)
156.

Measurement of increase in concentration of reactant and increase in concentration of product over a specific time period is called

A. rate of reaction
B. equilibrium reaction
C. rate determining step
D. none of above
Answer» B. equilibrium reaction
157.

Rate of reaction approx. doubles when temperature increases

A. approx. 50C
B. approx. 10 °C
C. approx. 15 °C
D. approx. 20 °C
Answer» C. approx. 15 °C
158.

Surface area is greater in

A. small particles
B. powdered particles
C. larger lumps
D. crystals
Answer» C. larger lumps
159.

Factors affecting speed of chemical reactions does not include

A. pressure on reactants
B. particle size of reactants
C. concentration of reactants
D. volume of reactants
Answer» E.
160.

MSG (Monosodium glutamate) is added in food

A. as a preservative
B. as a food flavourer
C. to enable quick cooking when consumed
D. to add scent
Answer» C. to enable quick cooking when consumed
161.

In graph of decrease in mass against time, fastest reaction shows

A. steepest curve
B. less steep
C. flat curve
D. a plateau
Answer» B. less steep
162.

Brazil has fewer oil reserves that's why they can grow a lot of sugar cane to produce

A. alcohol
B. ethanol
C. glucose
D. sugar
Answer» C. glucose
163.

Which is incorrect about the characteristics of Group II elements?

A. The metals act as reducing agents.
B. The metals are reduced when they react.
C. The metals of Group II loose electrons
D. The metals of Group II are reactive metals
Answer» C. The metals of Group II loose electrons
164.

Sugar cubes dissolve more slowly in hot drink than granulated sugar because

A. surface area of sugar cubes is less
B. surface area of granulated sugar is more
C. sugar cubes are acidic
D. both a and b
Answer» E.
165.

The activation energy of particular reaction is the minimum energy that is must for

A. reaction
B. collision
C. absorption
D. reduction
Answer» C. absorption
166.

Adsorption refers to the

A. bounding of a substance to the surface of another substance
B. diffusion of one substance to the bulk of other substances completely
C. boiling of liquid at the surface
D. an inability to bond something at the surface
Answer» B. diffusion of one substance to the bulk of other substances completely
167.

Carbonyl compounds when oxidized easily to form carboxylic group involves

A. aldehydes
B. ketones
C. haloalkanes
D. esters
Answer» B. ketones
168.

Which statement is correct about Group-II metals who have attraction of high nuclear charge?

A. it is because of the greater shielding effect
B. it makes the loss of electrons impossible
C. it is because of the distance from the nucleus
D. it outweighs the attraction of higher nuclear charge
Answer» E.
169.

The standard enthalpy change of combustion occurs when 1 mol of substance is burnt more than

A. nitrogen
B. oxygen
C. carbon dioxide
D. helium
Answer» C. carbon dioxide
170.

The electronegativity of Chlorine (Cl₂) is

A. 3.04
B. 3.16
C. 2.2
D. 2.55
Answer» C. 2.2
171.

In a certain volume, higher temperature

A. increases concentration of gases
B. decreases concentration of gases
C. liquefies the gases
D. the reaction may not occur at all
Answer» B. decreases concentration of gases
172.

Halogen with the highest electronegativity is

A. F
B. Br
C. Cl
D. I
Answer» B. Br
173.

Collision theory helps to explain the effects of

A. concentration
B. temperature
C. surface area
D. all of above
Answer» E.
174.

The proportion of successful collision increase with the increase in

A. solute
B. solvent
C. reactant
D. temperature
Answer» E.
175.

The rate of reaction is the change in the number of reactants or products in specific

A. volume
B. density
C. time
D. area
Answer» D. area
176.

First calculations on equilibrium were carried out by

A. Cato Guldberg only
B. Peter Waage only
C. John Dalton
D. Cato Guldberg and Peter Waage
Answer» E.
177.

The distribution of energy for temperature was given in

A. Boltzmann distribution
B. Boltzmann energy
C. Boltzmann temperature distribution
D. Boltzmann pressure
Answer» B. Boltzmann energy
178.

According to collision theory, the reaction speeds up when a frequency of reaction

A. decreases
B. increases
C. constant
D. equilibrium
Answer» C. constant
179.

The standard enthalpy change of neutralization involves the reaction of an acid with an alkali to form 1 mol of

A. water
B. oxygen
C. nitrogen
D. anhydrous salt
Answer» B. oxygen
180.

The slowest step on which overall reaction depends is

A. rate of reaction
B. rate equation
C. rate determining step
D. none of above
Answer» D. none of above
181.

Many catalysts are

A. noble gases
B. transition metals
C. non-metals
D. inert gases
Answer» C. non-metals
182.

If forward reaction is feasible then the reverse mechanism is

A. not feasible
B. possible
C. constant
D. highly probable
Answer» B. possible
183.

The pH of Mg(OH)₂ produced after Mg(s) and H₂O(l) reaction is

A. 1 to 4
B. 5 to 7
C. 8 to 11
D. 12 to 14
Answer» D. 12 to 14
184.

Some particles collide but bounce back afterward it is called

A. successful collision
B. unsuccessful collision
C. successful reaction
D. unsuccessful reaction
Answer» C. successful reaction
185.

An average size cigarette burns in 10 seconds

A. in pure hydrogen
B. in pure oxygen
C. in pure carbon dioxide
D. at room temperature
Answer» C. in pure carbon dioxide
186.

The enthalpy change when the number of reactants gives products under standard conditions is called standard enthalpy change of

A. reaction
B. formation
C. combustion
D. neutralization
Answer» B. formation
187.

The value of Eo is known as

A. standard electrode potential
B. standard cell potential
C. standard charge potential
D. standard ion potential
Answer» C. standard charge potential
188.

Order of reaction can be predicted by knowing that the rate-determining step have what

A. intermediates
B. reactants
C. products
D. initiators
Answer» B. reactants
189.

Nitric acid is a good

A. oxidizing agent
B. reducing agent
C. reactant
D. none of above
Answer» B. reducing agent
190.

Among zinc and copper, the greater tendency to lose electrons is of

A. copper
B. zinc
C. aluminum
D. nickel
Answer» C. aluminum
191.

If the reaction is likely to occur when we say that it is

A. feasible
B. impossible
C. constant
D. malleable
Answer» B. impossible
192.

Upon reaction of metals of Group II with oxygen, electrons are lost more easily by

A. larger atoms of Group-II
B. smaller atoms of Group-II
C. larger atoms of Group-III
D. smaller atoms of Group-III
Answer» B. smaller atoms of Group-II
193.

A colorimeter helps to measure in a reaction mixture its

A. progress
B. reactants
C. products
D. temperature
Answer» B. reactants
194.

What is true about Carbon dioxide?

A. it enhances global warming only
B. it is pollutant only
C. it is toxic
D. it enhances global warming and it is pollutant
Answer» E.
195.

The system will not be in equilibrium when there is an increase in concentration of

A. reactants
B. products
C. catalysts
D. activation energy
Answer» C. catalysts
196.

Consider the reaction: Al(s) + O₂ (g) → Al₂O₃. Moles of Al(s) needed to balance the equation are

A. 1
B. 2
C. 3
D. 4
Answer» E.
197.

A saturated solution of lead (II) contains 0.99g per 100 g of water, therefore it is regarded as

A. saturated solution
B. unsaturated solution
C. insoluble
D. soluble
Answer» D. soluble
198.

The problem of enhanced global warming is due to the vast amount of CO₂ produced by a human from past

A. 100 years
B. 200 years
C. 300 years
D. 400 years
Answer» C. 300 years
199.

The condition of Mg in which it reacts violently with water is

A. Mg(s) while cold
B. Mg(s) when heated
C. Mg(s) at normal temperature
D. none of above
Answer» C. Mg(s) at normal temperature
200.

Upon the reaction: SiCl₄(l) + 2H₂O(l) → SiO₂(s) + HCl(g), the solution becomes ionic because

A. H⁺ are produced.
B. the gaseous HCl is formed
C. some of the HCl(g) can get dissolved in water
D. all of above
Answer» E.