Chemistry Questions

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  substances  cause temporary hardness in water?

1. Mg(HCO3)2

2. Ca(HCO3)2

3. CaCl2

4. MgSO4

Atmosphere of Venus mostly contains which of the following gases? 

Which one of the following statements would be INCORRECT to use?

Ionic compounds ______.

I. have high boiling point

II. have high melting point

III. conduct electricity in solution

_______contributes towards global warming so it is called a greenhouse gas.

In a combination reaction there can be ______.

I. two or more than two reactants

II. two or more than two products

III. only one product

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.