Science : Ch 01 – Chemical Reactions and Equations

Give an example of decomposition reaction taking place in our body.

What happens when sodium sulphate solution is added to barium chloride solution?

Why are anti-oxidants added to fat and oil containing food items?

Identify the reducing agent in the following reactions 4NH₃ + 5O₂ → 4NO + 6H₂O

Identify the reducing agent in the following reactions: 2H₂O + 2F₂ → 4HF + O₂

Identify the reducing agent in the following reactions: Fe₂O₃ + 3CO → 2Fe + 3CO₂

Identify the reducing agent in the following reactions: 2H₂ + O₂ → 2H₂O

State the reactions exothermic or endothermic in nature: Dilution of sulphuric acid

In the electrolysis of water, name the gases liberated at cathode

Electrolysis of water is a decomposition reaction. The mole ratio of hydrogen and oxygen gases liberated during the electrolysis of water is:

One of the following does not happen during a chemical reaction.

You are given the solution of lead nitrate. In order to obtain a yellow precipitate you should blend with it a solution of:

Dilute hydrochloric acid is added to granulated zinc taken in a test tube. The following observations are recorded. Designate the accurate observation:

The following reaction is an example of a: 4NH₃(g) + 5O₂(g) → 4NO(g) + 6H₂O(g)

1. Displacement reaction
2. Combination reaction
3. Redox reaction
4. Neutralisation reaction

Three beakers labelled as A, B and C, each containing 25 ml of water, were taken. A small amount of NaOH, anhydrous CuSO4 and NaCl were added to the beakers A, B and C respectively. It was observed that there was an increase in the temperature of the solutions contained in beakers A and B, whereas in the case of beaker C, the temperature of the solution fell. Which one of the following statement(s) is (are) correct?

1. In beakers A and B, exothermic process has occurred.
2. In beakers A and B, endothermic process has occurred
3. In beaker C, exothermic process has occurred
4. In beaker C, endothermic process has occurred.