Chemistry Questions

Which of the following statements is/are true or false?

Statements :

A) H2S burns in air to give H2O and SO2

B) The decomposition of Ferrous Sulphate into Fe2O3, SO2 and SO3 occurs in the presence of heat.

Plaster of Paris ______.

I. changes into gypsum on mixing with water

II. is CaSO4.2H2O

III. is used for decoration

Which of the following statements are CORRECT?

I. Esters are sweet smelling substance.
II Esters are used in making perfumes.
III. Functional group of ester is R-O-RꞋ.

Which of the following statements are CORRECT?

I. Oxides of metals are generally basic.

II. Oxides of non-metals are generally acidic.

III. Non-metals are generally electro positive.

____ are atoms/molecules/ions containing the same number of electrons.

Which  of  the  following  substances  cause temporary hardness in water?

1. Mg(HCO3)2

2. Ca(HCO3)2

3. CaCl2

4. MgSO4

Which of the following statements are CORRECT?

I. Ethanol is a good solvent for organic compounds.

II. Boiling and melting points of ethanol are low with respect to water.

III. Ethanol is used tincture iodine

Valency of an element depends on which of the following?

I. Number of losing electron

II. Number of gaining electron

III. Number of sharing electron