Metals and Non-Metals — Science STD 10 — Question

Hydrolysis of water is:

Which among the following statement(s) is (are) true? Exposure of silver chloride to sunlight for a long duration turns grey due to:

1. The formation of silver by decomposition of silver chloride.
2. Sublimation of silver chloride.
3. Decomposition of chlorine gas from silver chloride.
4. Oxidation of silver chloride.

1. 1 Only
2. 1 and 3
3. 2 and 3
4. Only 4

An element X reacts with hydrogen, when heated, to form a covalent hydride H₂X. If H₂X has a smell of rotten eggs, the element X is likely to be:

One of the following is not an organic acid. This is:

1. Ethanoic acid.
2. Formic acid.
3. Citric acid.
4. Carbonic acid.

A student takes Na₂CO₃ powder in a test tube and pours some drops of acetic acid over it. He observes:

The number of molecules of water of crystallisation present in washing soda crystals is:

1. Five.
2. Two.
3. Ten.
4. Seven.

Of the three kinds of elements, which is the least conductive?

An ore of manganese metal is:

The number of times the substituent group occurs is indicated by:

Zone refining is used for the: