Some Chemical Reactions MCQs with Answers

In an acidic medium, methyl orange is red and in a basic medium, it is?

• A.Blue
• B.Colourless
• C.Yellow
• D.Green

When an acid reacts with an alkali, the reaction is called?

• A.Neutralization reaction
• B.Oxidation reaction
• C.Reduction reaction
• D.Precipitation reaction

Which one of the following types of change occurs when both the appearance and composition of a substance change?

• A.Physical change
• B.Chemical change
• C.Reversible change
• D.Temporary change

The reaction H2 + I2 ⇌ 2HI is independent of ?

• A.Pressure
• B.Temperature
• C.Catalyst
• D.Concentration of reactants

Titration of a strong acid against a weak base mainly proceeds via a/an _?

• A.Neutralization reaction
• B.Redox reaction
• C.Precipitation reaction
• D.Decomposition reaction

In open atmosphere iron rusts, which is chemically?

• A.Iron Oxide
• B.Iron Sulphide
• C.Iron Carbonate
• D.Iron Hydroxide

Reduction involves:

• A.Gain of electrons
• B.Loss of electrons
• C.Gain of protons
• D.Loss of protons

The product formed when a Grignard reagent reacts with carbon dioxide (CO₂) followed by hydrolysis is?

• A.Alcohol
• B.Aldehyde
• C.Carboxylic acid
• D.Ketone

The reaction which releases or gives off heat is called?

• A.Endothermic Reaction
• B.Exothermic Reaction
• C.Isothermic Reaction
• D.Adiabatic Reaction

Activation energy is?

• A.Maximum energy released during a reaction
• B.Energy absorbed after a reaction completes
• C.Energy stored in chemical bonds
• D.Minimum energy needed to start a reaction