Miscellaneous And Useful Chemical Compounds (Part-I)

11. Nitric acid does not react with— [S.S.C. Online Graduate Level (T-I) 31.08.2016 (Shift-II)]

(a) Gold
(b) Copper
(c) Zinc
(d) Iron

Correct Answer: (a) Gold

Solution:Gold generally does not react with any acid, but it quickly dissolves in aqua regia, which is a mixture of one part nitric acid and three parts hydrochloric acid. In the above options, nitric acid reacts with all others except gold.

12. An acid converts _____ to litmus. [S.S.C. Online CHSL (T-I) 11.01.2017 (Shift-I)]

(a) Red, Blue
(b) Green, Yellow
(c) Blue, Red
(d) Yellow, Green

Correct Answer: (c) Blue, Red

Solution:An acid is a chemical compound that dissolves in water to give hydrogen ions (H⁺). Its pH value is less than 7. Acid turns blue litmus paper red.

13. Litmus paper changes to _____ colour when put in soap water. [S.S.C. Online CHSL (T-I) 06.08.2021 (Shift-II)]

(a) yellow
(b) orange
(c) red
(d) blue

Correct Answer: (d) blue

Solution:Soap is made by means of basic salts. Hence the aqueous solution of soap or the value of soap becomes alkaline. Therefore, the litmus paper put in it turns blue, because litmus gives blue color with alkali.

14. Acids turn blue litmus paper into which color? [S.S.C. Online MTS (T-I) 21.09.2017 (Shift-II)]

(a) Green
(b) Red
(c) Pink
(d) Colorless

Correct Answer: (b) Red

Solution:All acids, if contacted with litmus paper, turn blue litmus paper red. Acids and bases are recognized by litmus. Red litmus paper is used to identify bases because bases turn red litmus blue.

15. Blue litmus paper turns _____ on contact with an acidic solution. [S.S.C. Online Graduate Level (T-I) 12.06.2019 (Shift-II)]

(a) red
(b) yellow
(c) brown
(d) green

Correct Answer: (a) red

16. During the fermentation of sugar, the compound which is always formed is— [S.S.C. Online Graduate Level (T-I) 9.09.2016 (Shift-II)]

(a) Methyl Alcohol
(b) Ethyl Alcohol
(c) Acetic Acid
(d) Ethylene

Correct Answer: (b) Ethyl Alcohol

Solution:During the fermentation of sugar, ethyl alcohol is formed and carbon dioxide gas is formed.
C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂ + Energy

17. Ethanol is produced by which process? [S.S.C. Online Constable GD 2.03.2019 (Shift-I)]

(a) Salinization
(b) Combination
(c) Titration
(d) Fermentation

Correct Answer: (d) Fermentation

Solution:The chemical formula of ethanol or ethyl alcohol is C₂H₅OH.

18. What will be the formula of fructose? [C.P.O. S.I. 6.06.2016 (Shift-I)]

(a) C₁₂H₂₂O₁₁
(b) C₆H₁₂O₆
(c) C₁₂H₁₉Cl₃O₈
(d) C₆H₁₀O₅

Correct Answer: (b) C₆H₁₂O₆

Solution:The chemical formula of fructose is C₆H₁₂O₆. It is a monosaccharide found in sweet fruits. Fructose is soluble in water, alcohol, or ether.

19. _____ the correct formula for ammonium phosphate [S.S.C. Online MTS (T-I) 9.10.2017 (Shift-I)]

(a) NH₄H₂PO₄
(b) (NH₄)₂PO
(c) (NH₄)₃PO₄
(d) (NH₄)₂PO₄

Correct Answer: (c) (NH₄)₃PO₄

Solution:The formula for ammonium phosphate is [(NH₄)₃PO₄].

20. Which of the following acts as best adsorbent? [S.S.C. Online Graduate Level (T-I) 9.09.2016 (Shift-II)]

(a) Charcoal
(b) Activated Charcoal
(c) Activated Coconut Charcoal
(d) Carbon Black

Correct Answer: (c) Activated Coconut Charcoal

Solution:Activated coconut charcoal is the best adsorbent among the given options. It is also useful in making masks and has a relatively high ability to absorb toxic gases.