Question

1. a pfd is different from a pid because it a) is less detailed b) uses equipment and data c) calculates yields d) has different arrows 22. mass - balance ensures that: a) inputs equal outputs plus accumulation b) yields are always 100% c) energy is conserved d) all equipment is 100% safe 23. if a separator malfunctions, the product will likely: a) be off - spec b) improve yield c) stay unchanged d) increase profits 24. in an example with 500 kg feed, 300 kg product, and 180 kg waste, the missing mass is: a) 20 kg b) 80 kg c) 200 kg d) none 25. what could explain the missing mass? a) extra product b) leaks or measurement errors c) more yield d) extra equipment 26. why is identifying missing mass important? a) it helps prevent safety risks b) it ensures off - spec products c) it lowers yield d) it replaces diagrams 27. if a pfd is ignored, technicians may: a) miss equipment details b) increase safety

Explanation:

Step1: Solve question 24

According to the law of mass - balance, the total input mass should equal the sum of output mass and waste mass. Let the missing mass be $x$. The input mass is $500$ kg, the product mass is $300$ kg, and the waste mass is $180$ kg. So, $500=300 + 180+x$. Solving for $x$, we get $x=500-(300 + 180)=20$ kg.

Step2: Solve question 25

The most likely reason for missing mass is leaks or measurement errors. Extra product would increase the measured product mass, more yield would also increase the product - related mass, and extra equipment has no direct relation to mass imbalance.

Step3: Solve question 26

Identifying missing mass is important because it helps prevent safety risks. Off - spec products are not related to mass balance in this context, lowering yield is not a positive outcome of identifying missing mass, and it has nothing to do with replacing diagrams.

Step4: Solve question 27

If a PFD (Process Flow Diagram) is ignored, technicians may miss equipment details. Ignoring a PFD does not increase safety.

Answer:

1. a) 20 kg
2. b) Leaks or measurement errors
3. a) It helps prevent safety risks
4. a) Miss equipment details