Question

b) pump
c) reactor
d) heat exchanger

1. how is a process flow diagram (pfd) different from a block flow diagram (bfd)?

a) pfds are simpler
b) pfds include equipment symbols and data
c) pfds exclude stream directions
d) pfds only show waste products

1. what does mass balance ensure?

a) inputs equal outputs plus accumulation
b) every product meets specifications
c) all waste is recycled
d) equipment never malfunctions

1. if 500 kg enters a system and 300 kg of product + 180 kg of waste leaves, what is the missing mass?

a) 10 kg
b) 20 kg
c) 30 kg
d) 50 kg

1. why is mass balance important?

a) it reduces paperwork
b) it guarantees higher yield
c) it confirms materials are accounted for and processes are stable
d) it shows when to skip equipment steps
writing response: in 5 - 6 sentences, explain how unit operations and mass balance work together to keep processes safe, efficient, and reliable. use examples from the passage.

Explanation:

Step1: Analyze question 6

A Process - Flow Diagram (PFD) includes equipment symbols and data, while a Block - Flow Diagram (BFD) is more general.

Step2: Analyze question 7

Mass balance is based on the principle that inputs equal outputs plus accumulation.

Step3: Analyze question 8

Calculate the sum of output mass: $300 + 180=480$ kg. Then find the missing mass: $500−480 = 20$ kg.

Step4: Analyze question 9

Mass balance is important as it confirms materials are accounted for and processes are stable.

Answer:

1. B. PFDs include equipment symbols and data
2. A. Inputs equal outputs plus accumulation
3. B. 20 kg
4. C. It confirms materials are accounted for and processes are stable