# Class 11 Chemistry MCQ – States of Matter – Liquid State

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This set of Class 11 Chemistry Chapter 5 Multiple Choice Questions & Answers (MCQs) focuses on “States of Matter – Liquid State”.

1. What is the boiling point at pressure 1 atm known as?
a) Standard boiling point
b) Normal boiling point
c) Van der Waal boiling point
d) Saturated boiling point

Explanation: The boiling point at pressure 1 atm is known as normal boiling point. Normal boiling point is slightly greater than the standard boiling point as molecules change into the vapor phase and density of vapor increases.

2. 1 poise = ____________
a) 0.1 kgm-1s-1
b) 1 kgm-1s-1
c) 10 kgm-1s-1
d) 100 kgm-1s-1

Explanation: Poise is the unit of viscosity. It’s S.I. unit is 1 Newton second per square meter. It’s Pascal second. In C.G.S. system, the unit of viscosity is poise that is named after a scientist Jean Louise
Poiseuille. So, it’s 1 poise = 0.1 kgm-1s-1.

3. Viscosity of liquid _________ with rise in temperature.
a) Increases
b) Decreases
c) Remains constant
d) Is independent

Explanation: As there is a rise in temperature the viscosity of liquid increases while the viscosity of gas decreases. In liquids, due to rise in temperature, molecules have high thermal energy so the can overcome intermolecular attractions.
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4. In a liquid, the force required to maintain the flow of layers is 5N, velocity gradient in du/dx, area of contact is 20m2. Then what is the value of viscosity?
a) 6.25 dz/du
b) 0.15 dz/du
c) 0.2 dz/du
d) 0.25 dz/du

Explanation: The formula of force required to maintain the flow of layers is given by the formula F = ηAdu/dz, where η is the coefficient of viscosity, A is the area of contact and du/dz is the velocity gradient. So by substituting we get an answer as 0.25dz/du.

5. Path in liquid in which layers do not meet each other is _______
a) laminar flow
b) tubular flow
c) viscosity
d) straight path

Explanation: The type of flow in liquids when each path flows in a different path, that do not interfere with each other is laminar flow. At any point in the fluid, the velocity of a fluid is constant is a characteristic of laminar flow.

6. What is S.I. unit of Surface Tension?
a) Dyne/meter
b) Newton-meter
c) Newton/meter
d) Dyne-meter

Explanation: Surface Tension is the tendency of a fluid to occupy least surface area as possible. It is defined as the force per unit distance. So, the units of surface tension are Newton/meter in S.I. the system, Dyne/cm in C.G.S system.

7. If the angle of contact between the liquid and container is 90 degrees then? (C is the cohesive and A is the Adhesive force)
a) C > A
b) C = A
c) C < A
d) C is not equal to A

Explanation: When the angle of contact between the liquid and container is 90 degrees then the cohesive and adhesive forces in a liquid are equal. Cohesive force is the attraction between similar atoms and adhesive between different atoms.

8. A water drop is spherical in shape due to ____________
a) Viscosity
b) Poise
c) Surface tension
d) Reflection

Explanation: Surface Tension is the tendency of a fluid to occupy least surface area as possible. It is defined as the force per unit distance. So, the spherical shape that is acquired by a water drop is due to surface tension.

9. The surface tension of ___________ at critical temperature.
a) one
b) zero
c) two
d) three

Explanation: The surface tension in liquids decreases with rise in temperature. As surface tension decreases, molecules become more active when temperature increases and surface tension becomes zero at critical temperature TC.

10. Higher the viscosity, the slower the liquid flows.
a) True
b) False

Explanation: Viscosity is defined as the resistance to the flow of a liquid. It opposes a liquid’s layer movement with respect to one another. So, the above statement: the higher the viscosity, the slower the liquid flows is true.

Sanfoundry Global Education & Learning Series – Chemistry – Class 11.

To practice all chapters and topics of class 11 Chemistry, here is complete set of 1000+ Multiple Choice Questions and Answers. 