Biochemistry Questions and Answers – Water as a Reactant

This set of Biochemistry Multiple Choice Questions & Answers (MCQs) focuses on “Water as a Reactant”.

1. The processes i and ii are respectively.

i) CuSO4 + 5H2O  CuSO4.5H2O
ii) PCl3  + 3H2O  H3PO3  + 3HCl

a) Hydration and dehydration
b) Hydration and hydrolysis
c) Hydrolysis and hydrolysis
d) Hydration and hydration
View Answer

Answer: b
Explanation: Process A involves absorption of water and B involves double decomposition reaction.

2. Which of the following is not a condensation reaction?
a) ADP + inorganic phosphate ATP + H2O
b) R-OH + inorganic phosphate phosphate ester + H2O
c) R-COOH + inorganic phosphate Acyl phosphate + H2O
d) 6CO2 + 6 H2O C6H12O6 + 6CO2
View Answer

Answer: d
Explanation: Condensation reaction involves elimination of water molecules.
advertisement
advertisement

3. Which of the following is the correct equation?
a) CO2 + H2O H2CO3
b) CO2 + H2O HCO3
c) CO2 + H2O H3CO3
d) CO2 + H2O H2CO2
View Answer

Answer: a
Explanation: The correct balanced equation is CO2 + H2O H2CO3. Carbondioxide reacts with water to give carbonic acid.

4. Consider the following reaction, in the presence of light

2H2O + 2X  O2 + 2XH2
Note: Join free Sanfoundry classes at Telegram or Youtube

Which of the following statements is true?
a) X is electron-accepting specie
b) X is electron-donating specie
c) Water is an electron acceptor
d) Water neither donates nor accepts any electron
View Answer

Answer: a
Explanation: In this oxidation reduction sequence, water serves as the electron donor and X serves as an electron acceptor.

5. Hydrolysis reactions are catalyzed by enzymes called ___________
a) Oxidoreductase
b) Ligase
c) Hydrolase
d) Isomerase
View Answer

Answer: c
Explanation: Hydrolases, which catalyze hydrolysis reaction involve in food decomposition and in digestion process.
advertisement

6. What does it mean when we say that water acts as a “heat buffer”?
a) It keeps the temperature of an organism relatively constant as the temperature of the surroundings fluctuates
b) It increases the temperature of an organism as the temperature of the surroundings increases
c) It decreases the temperature of an organism as the temperature of the surroundings increases
d) It increases the temperature of an organism as the temperature of the surroundings decreases
View Answer

Answer: a
Explanation: Water has a high specific heat capacity, it is hard to increase or decrease the water temperature which requires a lot of heat energy and therefore water acts as a heat buffer.

7. Which of the following does not react with water?
a) Barium
b) Calcium
c) Beryllium
d) Strontium
View Answer

Answer: c
Explanation: Be is the only alkaline earth metal which does not react with water.
advertisement

8. What trend does the reactivity of group II elements follow with water?
a) Increases down the group
b) Decreases down the group
c) Does not follow any particular trend
d) No reaction
View Answer

Answer: a
Explanation: As we descend down the group, losing of electrons from the outer orbit of an atom becomes easy.

9. Which among the following statements is true about the following chemical reaction?

3Fe(s) + 4H2O → Fe3O4 (s) + 4H2

a) Iron metal is getting reduced
b) Water is acting as a reducing agent
c) Water is acting as an oxidizing agent
d) Water is getting oxidized
View Answer

Answer: c
Explanation: Water is getting reduced and it oxidizes iron metal, thus acting as an oxidizing agent.

10. Identify the products formed in the following reaction.

CH3 COOCH3 + H2O → A + B

a) CH3 COOH and CH3OH
b) CH3 COOOH and CH4
c) CO2 and C2H6
d) No reaction
View Answer

Answer: a
Explanation: Ester Hydrolysis
CH3 COOCH3 + H2O → CH3COOH + CH3OH.

Sanfoundry Global Education & Learning Series – Biochemistry.

To practice all areas of Biochemistry, here is complete set of 1000+ Multiple Choice Questions and Answers.

advertisement
advertisement
Subscribe to our Newsletters (Subject-wise). Participate in the Sanfoundry Certification contest to get free Certificate of Merit. Join our social networks below and stay updated with latest contests, videos, internships and jobs!

Youtube | Telegram | LinkedIn | Instagram | Facebook | Twitter | Pinterest
Manish Bhojasia - Founder & CTO at Sanfoundry
Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He lives in Bangalore, and focuses on development of Linux Kernel, SAN Technologies, Advanced C, Data Structures & Alogrithms. Stay connected with him at LinkedIn.

Subscribe to his free Masterclasses at Youtube & discussions at Telegram SanfoundryClasses.