Question

[Viscosity Questions] about chemistry: (multiple choice about viscosity) Please help. Thanks!! Explain each one thanks!

1. A fluid is considered "Newtonian" if:
a) it experience laminar flow
b) η is independent of the velocity gradient
c) η is a constant
d) the shearing force is exerted in the direction of the flow
e) all of the above

2. The viscosity η is a function of:
a) temperature
b) Pressure
c) composition
d) volume
e) a, b, and c are correct

3. A flow is considered turbulent if:
a) R> 2000
b) R <2000
c) R = 2000
d) R = 0
e) R> 10000

4. Temperature (T) and density (ρ) increase viscosity if:
a) T goes up, ρ goes down
b) T goes down, ρ goes up
c) T goes up, ρ goes up
d) T low, ρ low
e) c and d are correct

5. The surface tension in liquids is attributed to:
a) the force of gravity
b) changes in atmospheric pressures
c) total surface area
d) intermolecular forces
e) all of the above

6. About the surface tension, y, the following can be said:
a) this acts along the surface
b) tends to make the surface area as small as possible
c) It is a liquid surface property - gas
d) its value is zero when the system reaches the critical temperature
e) all of the above

Answer 1

The answers are 1- e, 2- a, b, d, 3- a, 4- c, 5- c,d, 6-e

Answer - e all of the the above. explaination - A fluid is called hewtonian it and only if it experience laminar I low, the tensor that describle the viscous stress and strain rate are related by a constant viscosity tensor (n) which does not depend on the stress and strain rate and the shearing force is exerted in the direction of the flow. The viscosity on is a function of a temperature, b) Pressure , d) volume 27 explaination - viscosity n = A e-tall where T = temp. and n = re Pp4 +/8 ve where P = pressure ta time v zvolume De

answer - explanation turbulent is greater ax R > 2000 - A flow is called if the Reynolds number (R) than 2000. answers explaination. Te imperature (t)and density (A) increase xlscosity if c) - T goes up, p goes up. nat and n a V or, nap because - 5 answer - ) and d) explanation - The surface tension of a liquiel is attributed to total surface are and intermolecular fores. auswer – e) all of the above explanation - All of the above said properties in the options are some property of surface tension or related to it.