Soil conservation is the process where

1. Soil is aerated

2. Soil erosion is allowed

3. Soil is protected against loss

4. Sterile soil is converted into fertile soil

The Lassaigne's extract is boiled with conc. $HN{O}_3$  while testing for the halogens. By doing so, it:

1. decomposes $N{a}_{2}S$ and NaCN, if formed.

2. helps in the precipitation of AgCl.

3. increases the solubility product of AgCl.

4. increases the concentration of $N{O}_3^{-}$ ions.

Ether and benzene can be separated by :-

(1) Filtration

(2) Distillation

(3) Crystallization

(4) Sublimation

... is not a greenhouse gas :-
1. Hydrogen
2. Carbon dioxide
3. Methane
4. Nitrous oxide or $N_{2}O$

In Kjeldahl's method for estimation of nitrogen present in a soil sample, ammonia evolved from 0.75 g of sample neutralized 10 mL of 1 M $H_{2}S{O}_4$. The percentage of nitrogen in the soil is:

(1) 37.33

(2) 45.33

(3) 35.33

(4) 43.33

The concentration of Peroxy Acetyl Nitrate (PAN) maximum in:-

(1) Fog

(2) Smoke

(3) Smog

(4) Photochemical smog

Soil erosion can be prevented by : 

1. Overgrazing

2. Removal of vegetation

3. Afforestation (Plantation)

4. Increasing bird population

Soil erosion is greater when

(1) No rain occurs

(2) Winds do not blow

(3) The rainfall is evenly distributed

(4) The Rainfall is received in heavy down pour

Acid rain is due to an increase in the atmospheric concentration of : 

1. Ozone, and dust

2. $C{O}_{\mathrm{2,}}$ and CO

3. $S{O}_{\mathrm{3,}}$ and CO

4 $S{O}_{\mathrm{2,}}$ and $N{O}_2$

B.O.D is connected with

(1) Organic matter

(2) Microbes

(3) Both

(4) None