11.5 Alcohols — Chemistry STD 10 — Question

Name the metal hydroxides which are :
(a) Insoluble (b) Soluble in
(i) Caustic soda solution (ii) Ammonium hydroxide solution.

Write the observation, and balanced equation for the following reaction:
Moist starch iodide paper is placed at the mouth of a test tube containing chlorine gas.

Three different electrolytic cells A, B and C are connected in separate circuits. Electrolytic cell A contains sodium chloride solution. When the circuit is completed a bulb in the circuit glows brightly. Electrolytic cell B contains acetic acid solution and in this case the bulb in the circuit glows dimly. The electrolytic cell C contains sugar solution and the bulb does not glow. Give a reason for each of these observations.

Explain the following briefly.
Pure water does not conduct electricity, but on adding sodium chloride to it, it starts conducting electricity.

(a) Why do the halogen atoms have a very strong electron affinity? Explain.
(b) Arrange Br, F, I and Cl in the order of increasing electron affinity.

A compound gave a following data:
C = 57.82%, O = 38.58% and the rest hydrogen. Its relative molecular mass is 166.
Find its empirical formula and molecular formula.
[C = I2, O = 16, H = 1]

What is the difference in molecular formula of any Two adjacement homologues in terms of types of atoms and molecular mass?

Solve the following :
The vapour density of a gas is 8. What would be the volume occupied by 24.0 of the gas at STP?

The gases chlorine, nitrogen, ammonia and sulphur dioxide are collected under the same conditions of temperature and pressure. The following table gives the volumes of gases collected and the number of molecules (x) in 20 litres of nitrogen. You are to complete the table giving the number of molecules in the other gases in terms of x.

Gas	Volume (in litres)	Number of molecules
Chlorine Nitrogen Ammonia Sulphur dioxide	10 20 20 5	x