Board exam

Select from the following a decomposition reaction in which source of energy for decomposition is light :

1. A2FeSO₄ → Fe₂O₃ + SO₂ + SO₃
2. B2H₂O → 2H₂ + O₂
3. C2AgBr → 2Ag + Br₂
4. DCaCO₃ → CaO + CO₂

A metal and a non-metal that exists in liquid state at the room temperature are respectively :

1. ABromine and Mercury
2. BMercury and Iodine
3. CMercury and Bromine
4. DIodine and Mercury

Carbon compounds :

1. (i)
   are good conductors of electricity.
2. (ii)
   are bad conductors of electricity.
3. (iii)
   have strong forces of attraction between their molecules.
4. (iv)
   have weak forces of attraction between their molecules. The correct statements are :

Consider the following compounds : FeSO₄ ; CuSO₄ ; CaSO₄ ; Na₂CO₃ The compound having maximum number of water of crystallisation in its crystalline form in one molecule is :

1. AFeSO₄
2. BCuSO₄
3. CCaSO₄
4. DNa₂CO₃

Oxides of aluminium and zinc are :

1. Aacidic
2. Bbasic
3. Camphoteric
4. Dneutral

MnO₂ + 4HCl → MnCl₂ + 2H₂O + Cl₂ The reaction given above is a redox reaction because in this case :

1. AMnO₂ is oxidised and HCl is reduced.
2. BHCl is oxidised.
3. CMnO₂ is reduced.
4. DMnO₂ is reduced and HCl is oxidised.

Consider the following statements :

1. (i)
   The sex of a child is determined by what it inherits from the mother.
2. (ii)
   The sex of a child is determined by what it inherits from the father.
3. (iii)
   The probability of having a male child is more than that of a female child.
4. (iv)
   The sex of a child is determined at the time of fertilisation when male and female gametes fuse to form a zygote. The correct statements are :