Basic Chemical Engineering Questions and Answers Part-4

1. What is the specific gravity of 10 Kg of water occupied in 10 m3 with respect to 200 g/m3?
a) 0.2
b) 0.5
c) 1
d) 5

Answer: d
Explanation: Specific gravity = (10/10)/0.2 = 5.

2. What is the specific gravity of 5 Kg of water occupied in 10 m3 with respect to 500 g/m3?
a) 0.5
b) 1
c) 2
d) 5

Answer: b
Explanation: Specific gravity = (5/10)/0.5 = 1.

3. What is the specific gravity of 10 Kg of water occupied in 5 m3 with respect to 100 g/m3?
a) 1
b) 5
c) 10
d) 20

Answer: d
Explanation: Specific gravity = (10/5)/0.1 = 20.

4. What is the specific gravity of O2 at 27oC and 60 Pa with respect to 1 Kg/m3?
a) 0.15
b) 0.28
c) 0.54
d) 0.76

Answer: d
Explanation: Specific gravity = (60*32/8.314*300)/1 = 0.76.

5. What is the specific gravity of N2 at 27oC and 6 Pa with respect to 0.1 Kg/m3?
a) 0.16
b) 0.33
c) 0.51
d) 0.89

Answer: b
Explanation: Specific gravity = (6*14/8.314*300)/0.1 = 0.33.

6. Which of the following is the unit of flow rate?
a) Kg/s
b) Liters/s
c) Moles/s
d) All of the mentioned

Answer: d
Explanation: Mass flow rate = m/t, => unit = kg/s, volumetric flow rate = V/t, => unit = Liters/s, molar rate = n/t, => unit = moles/s.

7. Which of the following is not conserved for the flow of an incompressible liquid in a pipe with variable area?
a) Mass
b) Volume
c) Velocity
d) Flow Rate

Answer: c
Explanation: According to the equation of continuity, the product of area and velocity remains constant throughout the pipe, since the area of the pipe is variable, so the velocity if the liquid is variable.

8. What is the mass flow rate of a liquid flowing through a pipe of which 100 grams of water was collected in 10 seconds?
a) 0.01 kg/s
b) 0.05 kg/s
c) 0.1 kg/s
d) 0.5 kg/s

Answer: a
Explanation: mass flow rate = 0.1/ 10 = 0.01 kg/s.

9. What is the volumetric flow rate if 100 kg of water is collected in 10 seconds? (Density of water = 1000 kg/m3)
a) 0.1 m3/s
b) 0.2 m3/s
c) 0.01 m3/s
d) 0.02 m3/s

Answer: c
Explanation: volume of water collected = 100/1000 = 0.1 m3, => volumetric flow rate = 0.1/10 = 0.01 m3/s.

10. A liquid is flowing through a pipe of cross section 4 m2 at a rate of 4 kg/s, at a point pipe is divided into two pipes of areas of equal areas, what will be the ratio of flow rate in both the pipes?
a) 1:3
b) 1:1
c) 1:2
d) 2:3

Answer: b
Explanation: Since areas of the pipes are equal, by continuity equation flow will divide equally in the pipes, so their ratio will be 1:1.