Some Chemical Reactions MCQs with Answers

The conjugate acid of water (H₂O) is ?

• A.OH⁻
• B.H₃O⁺
• C.H₂O₂
• D.O₂

Vapour pressure of ethanol compared to water is _?

• A.Less than water
• B.Equal to water
• C.Greater than water
• D.Negligible compared to water

Lemon dissolution in water actually represents solute and solvent combination of ?

• A.Solid-liquid solution
• B.Gas-liquid solution
• C.Liquid-liquid solution
• D.Solid-solid solution

What is produced when biomass is dumped and decomposes?

• A.Syngas
• B.Bioethanol
• C.Biodiesel
• D.Biogas

The color developed by glycogen in iodine test ?

• A.Blue
• B.Yellow
• C.Violet
• D.Reddish-brown

A bottle of dilute hydrochloric acid is 2M. What mass of hydrogen chloride (HCl) would be dissolved in 100 cm³ of this acid?

• A.3.65 g
• B.7.3 g
• C.14.6 g
• D.36.5 g

The order of reactivity of following R-X for SN² reaction is ?

• A.RBr > RI > RCl > RF
• B.RF > RCl > RBr > RI
• C.RCl > RBr > RI > RF
• D.RI > RBr > RCl > RF

What happens when you put sand, salt and sawdust in a glass of water?

• A.Sand sinks, salt dissolves, sawdust floats
• B.Sand floats, salt sinks, sawdust dissolves
• C.Sand dissolves, salt floats, sawdust sinks
• D.All three dissolve completely

Basic Buffer solution can be prepared by mixing _?

• A.Weak acid and its salt with strong base
• B.Strong base and its salt with weak acid
• C.Strong acid and its salt with weak base
• D.Weak base and its salt with strong acid

An endothermic reaction is a chemical reaction that absorbs energy from its surroundings, usually in the form of heat. Which of the following reactions is endothermic?

• A.CaCO₃ → CaO + CO₂
• B.CH₄ + 2O₂ → CO₂ + 2H₂O
• C.2H₂ + O₂ → 2H₂O
• D.C + O₂ → CO₂