1. The ratio of water on our planet as compared to dry land is
(A) 76%
(B) 75%
(C) 77%
(D) 78%
2. The percentage of hydrogen to oxygen in water is
(A) 11.11% & 88.89%
(B) 12% & 88%
(C) 13% & 87%
(D) 10% & 90%
3. The bond angle between H–O–H is
(A) 104.2°
(B) 104.4°
(C) 104.3°
(D) 104.5°
4. The most readily soluble gas in water is
(A) O₂
(B) CO
(C) CO₂
(D) N₂
5. The water used in the boiler is
(A) Heavy water
(B) Soft water
(C) Hard water
(D) Common water
6. 1 PPM is equal to ______ mg/L
(A) 4
(B) 2
(C) 3
(D) 1
7. The isolation of salts from seawater is called
(A) Salinity
(B) Salivation
(C) Desalination
(D) Salts
8. The chemical name of water is
(A) Hydrogen oxide
(B) Hydroxide
(C) Hydrogen peroxide
(D) None of these
9. The alternate name for zeolite method is
(A) Ion exchange process
(B) Deionisation process
(C) Demineralisation process
(D) Permutit method
10. The formula of cation exchange resin is
(A) RH₃
(B) RH₂
(C) R(OH)₂
(D) R(OH)₃
11. Insoluble impurities that stick firmly to inner walls of boiler tubes are called
(A) Scale
(B) Sludge
(C) Silica
(D) All three
12. Insoluble impurities that remain suspended in boiler water are called
(A) Scale
(B) All three
(C) Silica
(D) Sludge
13. Used for internal treatment of scales in boiler
(A) Colloidal conditioning
(B) All three
(C) Calgon conditioning
(D) Phosphate conditioning
14. Prevention of ______ is most obligatory because it causes soil infertility and air pollution
(A) Salinity
(B) Soluble salts
(C) Hardness
(D) Pollution
15. Sewage treatment can be done by
(A) All three
(B) Secondary treatment
(C) Tertiary treatment
(D) Primary treatment
16. To make seawater fit for domestic use it is made pure by
(A) Sedimentation & filtration
(B) Desalination
(C) All three
(D) Sterilisation
17. Chemicals used to separate suspended impurities in seawater are
(A) Lime
(B) Silica
(C) Oxygen
(D) Alum & ferric chloride
18. Water used in boiler is usually made soft by method
(A) Zeolite
(B) Soda ash
(C) Lime soda
(D) All these three
19. For treatment of sewage water a huge amount of ______ is required
(A) O
(B) CO₂
(C) CO
(D) O₂