Chemistry

Chemical Reactions and Processes

571 Questions

Chemical reactions and processes questions cover the transformation of substances through electrolysis, thermal decomposition, and catalysis. Key areas include identifying gas evolution, balancing chemical equations, and understanding industrial chemical applications. This general chemistry topic is a staple in the science sections of multiple competitive examinations.

Thermal decompositionElectrolysis processGas evolution reactionsHeterogeneous catalystsFuel cell components

Chemical Reactions and Processes Questions

Multiple choice

Electrolysis of water gives oxygen and hydrogen and it is used for the industrial preparation of oxygen and hydrogen. Which of the following is correct about the above process?

  1. Oxygen is obtained at anode and hydrogen is obtained at cathode.

  2. Electrolysis of acidulated water is done as pure water does not allow electricity to pass through it.

  3. Both answers are correct.

  4. Both the above options are wrong.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Both of the above answers are correct.

Multiple choice

Which of the following statements is correct?

  1. Oxygen is lighter than air, so it is collected by the downward displacement of air.

  2. Phosphorous penta oxide is a basic gas which turns moist red litmus solution blue

  3. Sulphur forms neutral oxide when burned in oxygen.

  4. Metals like aluminium and zinc burn in oxygen to form their respective oxides, which are amphoteric in nature.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Correct. Aluminium and zinc form their respective amphoteric oxides; amphoteric oxides are compounds which show both acidic and basic character and can react with both acids and bases to form salt and water.

Multiple choice

What is true about the reaction N2 +O2 ---------> 2NO {presence of electric spark} that takes place in atmosphere at the time of lightning?

  1. The product formed is colourless, neutral and the reaction is endothermic.

  2. The product formed is reddish, neutral and the reaction is endothermic.

  3. The product formed is colourless, acidic and the reaction is endothermic.

  4. The product formed is colourless, neutral, and the reaction is exothermic.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Correct option. Nitric mono oxide is neutral and colourless and the reaction is endothermic.

Multiple choice

Magnesium, when burnt in the presence of oxygen, forms a new product. Which of the following statements is/are false regarding the chemical reaction that took place?

a. On burning in air, magnesium formed magnesium oxide. b. The change that took place was permanent and irreversible. c. No heat or light was evolved.

  1. Only a

  2. Only a and b

  3. Only b

  4. Only b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

This is the correct option. Heat and light were evolved when magnesium burnt in air to form magnesium oxide.

Multiple choice

If sodium carbonate is added to dil. sulphuric acid, sodium sulphate and water are formed, along with the release of a gas. Which of the following gases is released?

  1. Oxygen

  2. Helium

  3. Carbon dioxide

  4. Hydrogen

  5. Nitrogen
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is the correct option. If sodium carbonate is added to dil. sulphuric acid, sodium sulphate and water are formed, along with the release of carbon dioxide.

Na2CO3 + H2SO4 --> Na2SO4 + H2O + CO2  

Multiple choice

Which of the following statements is/ are false? P. In Raschig process hydrazine is prepared from the reduction of ammonia with sodium hypochlorite in dilute aqueous solution. Q. Borazine is known as inorganic benzene. R. Boric acid is a dibasic acid.

  1. Only P

  2. Only Q

  3. Only P and Q

  4. Only Q and R

  5. Only P and R
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

P) Hydrazine (N2H4) is a nitrogen hydride. In Raschig process it is prepared by the reaction of ammonia with sodium hypochlorite in dilute aqueous solution. Q) Borazine, B3N3H6 known as inorganic benzene in view of its ring structure with alternate BH and NH groups. R) Boric acid is a weak monobasic acid. It is not a protonic acid but acts as a Lewis acid by accepting electrons from a hydroxyl ion. Hence, statements P and R are false.