Carbon and its Compounds — Science STD 10 — Question

In order to study saponification reaction we first prepare 20% solution of sodium hydroxide. If we record the temperature of this solution just after adding sodium hydroxide flakes to water and also test its nature using litmus, it may be concluded that the process of making this solution is:

The number of carbon atoms in the organic compound named as 2,2-dimethylpropane is:

1. Two.
2. Five.
3. Three.
4. Four.

Which of the following cannot exhibit isomerism?

1. C₄H₁₀
2. C₅H₁₂
3. C₃H₈
4. C₆H₁₄

Plaster of Paris hardens by

The soap molecule has a:

1. Hydrophilic head and a hydrophobic tail.
2. Hydrophobic head and a hydrophilic tail.
3. Hydrophobic head and a hydrophobic tail.
4. Hydrophilic head and a hydrophilic tail.

If a few drops of a concentrated acid accidentally spills over the hand of a student, what should be done?

1. Wash the hand with saline solution.
2. Wash the hand immediately with plenty of water and apply a paste of sodium hydrogencarbonate.
3. After washing with plenty of water apply solution of sodium hydroxide on the hand.
4. Neutralise the acid with a strong alkali.

The metals which can produce amphoteric oxides are:

The aqua regia is:

During galvanisation, iron metal is given a thin coating of one of the following metals. This metal is:

1. Chromium.
2. Tin.
3. Zinc.
4. Copper.

A student puts one big iron nail each in four test tubes containing solutions of zinc sulphate, aluminium sulphate, copper sulphate and iron sulphate. A reddish brown coating was observed only on the surface of iron nail which was put in the solution of: