# MCQ on Water: Physical and Chemical Properties; pH and Buffer Systems Part 3 (Biochemistry MCQ-13)

(Sample/Model/Practice Questions for CSIR JRF/NET Life Science Examination, ICMR JRF Exam, DBT BET JRF Exam,, GATE BT and XL Exam, ICAR JRF NE Exam, PG Entrance Exam, JAM Exam, GS Biology Exam and Medical Entrance Exam)

(1). What is the molecular weight of water?

a.       10 g/mol
b.      15 g/mol
c.       18 g/mol
d.      20 g/mol

(2). What is the H+ ion concentration in pure water?

a.       1 X 10-7 m
b.      1 X 107 m
c.       1 X 10-14 m
d.      1 X 1014 m

(3). The equilibrium constant of ionization reaction of pure water is:

a.       1.8 X 10-14 M
b.      1.8 X 10-16 M
c.       1.8 X 10-7 M
d.      1.8 X 10-7 M

(4). The pH of pure water is neutral, the best explanation for this is:

a.       The pH of pure water is 7
b.      In pure water the concentration of H+ and OH are same
c.       Water do not contain free H+ or OH ions
d.      What will never ionize

(5). What is the concentration of OH ions in a solution with an H+ ion concentration of 1.3 X 10-4M?

a.       7.7 X 10-11 M
b.      7.7 X 10-10M
c.       1.4 X 10-11M
d.      1.4 X 10-10 M

# MCQ on Water, Hydrogen Bonds, pH Scale and Buffer Systems Part 2 (Biochemistry MCQ-12)

(Sample/Model/Practice Questions for CSIR JRF/NET Life Science Examination, ICMR JRF Exam, DBT BET JRF Exam,, GATE BT and XL Exam, ICAR JRF NE Exam, PG Entrance Exam, JAM Exam, GS Biology Exam and Medical Entrance Exam)

(1). Bond length between H and O atoms in water is:

a.       0.00965 nm
b.      0.0965 nm
c.       0.965 nm
d.      9.650 nm

(2). The van der Waals radius of Oxygen atom in water molecule is

a.       1.2 Å
b.      1.4 Å
c.       1.6 Å
d.      1.8 Å

(3). At room temperature and atmospheric pressure, a single water molecule can be hydrogen bonded with __________ water molecules.

a.       3.4
b.      3.0
c.       2.4
d.      1.4

(4). Non polar molecules are insoluble in water. This is because:

a.       Non polar molecules are uncharged
b.      Non polar molecules cannot be ionized
c.       Non polar molecules are unable to form water-solute interaction
d.      Hydrogen bond formation is not possible with non-polar molecules

(5). Which of the following is the correct for the formation of a hydrogen bond? (Hydrogen bond is represented as ‘…’)

a.       – O – H – O – H – X
b.      – O – H … O – X
c.       – O – H … H – O – X
d.      – O – H … C – O – X

# MCQ on Water, pH and Buffer Systems Part 1 (Multiple Choice Questions in Biochemistry MCQ-11)

(Sample/Model/Practice Questions for CSIR JRF/NET Life Science Examination, ICMR JRF Exam, DBT BET JRF Exam,, GATE BT and XL Exam, ICAR JRF NE Exam, PG Entrance Exam, JAM Exam, GS Biology Exam and Medical Entrance Exam)

(1). Water is liquid at room temperature, the most important reason for this is the:

a.  High boiling point of water
b.  High melting point of water
c.  High heat of vaporization of water
d.  Cohesive forces due to hydrogen bonds in water

(2). Water is a ___

a.  Polar solvent
b.  Non polar solvent
c.   An amphipathic solvent
d.   Non polar uncharged solvent

(3). Polar molecules can readily dissolve in water. This is because:

a.  Polar molecules can form hydrogen bonds with water
b.  Polar molecules can replace water-water interaction with more energetically favourable water-solute interactions
c.  Polar charged water can interact with the charge of polar molecules
d.  All polar molecules are amphipathic in nature

(4). Most important reason for the unusual properties of water is:

a. The covalent bonding pattern in water molecule
b.  The bond angle between the two hydrogen atoms in water
c.   Hydrogen bonding between water molecules
d.  Water can be immediately ionized at room temperature

(5). The H – O – H bond angle in water molecule is:

a.   104.0o
b.   104.5o
c.   105.0o
d.   105.5o