Chemical Reactions and Equations — Science STD 10 — Question

The elements A, B, C and D belong to groups 1, 2, 14 and 17 respectively of the periodic table. Which of the following pairs of elements would produce a covalent bond?

1. A and D.
2. C and D.
3. Aand B.
4. B and C.
5. Aand C.

Which of the following statements is correct about an aqueous solution of an acid and of a base?

1. Higher the pH, stronger the acid.
2. Higher the pH, weaker the acid.
3. Lower the pH, stronger the base.
4. Lower the pH, weaker the base.

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

Which of the following gives the correct increasing order of acidic strength?

1. Water < acetic acid < hydrochloric acid.
2. Water < hydrochloric acid < acetic acid.
3. Acetic acid < water < hydrochloric acid.
4. Hydrochloric acid < water < hydrochloric acid.

Although metals form basic oxides, which of the following metals form an amphoteric oxide?

On moving from left to right in a period in the periodic table, the size of the atom.

1. Increases.
2. Decreases.
3. Does not change appreciably.
4. First decreases and then increases.

Which of the following non-metal is a liquid?

1. Carbon.
2. Sulphur.
3. Bromine.
4. Iodine.

Which of the following is a natural indicator?

Which of the following is not an endothermic reaction?

One of the following substances is not added to make denatured alcohol. This is:

1. Methyl alcohol.
2. Copper sulphate.
3. Chloroform.
4. Pyridine.

Which of the following gives the correct increasing order of acidic strength?