Chemistry Lab Question: Calculating Water Usage in a Plant's Production Process

[Choronzon]

Homework Statement

A plant takes in 20.24 kg/day Al, 24.04 kg/day S8, 48.00 kg/day 02, and 753 kg/day H2O. It's product stream is 254.3 kg/day AlSO4+12(H2O). The rest of it's water goes to "other things".

How much water goes to other things?

Homework Equations

20.24+24.04+48.00+753=845.28 kg - 254.3 = 590.98 kg = 591 L/d

The Attempt at a Solution

I added the masses of the raw materials, subtracted the mass of the product stream, and the remainder is the water used for "other things."

It seems easy enough to me, but the simplicity of the question is giving me pause, as it's the first question in this course which seemed this simple. My result was 591 L/d.

Basically I want to know if I did this correctly, or am I barking up the completely wrong tree. If I'm wrong, I'd appreciate it if someone told me, but left it at that, as I'd like to try and figure it out on my own.

Thanks in advance.

 

[Borek]

Your intuition is right - it is not a correct answer.

Only part of the 254.3 kg is water.

Then, I have never seen compound with formula AlSO₄.

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methods

 

[Blueshift5]

Your approach is correct. You correctly calculated the amount of water used in the production process by subtracting the mass of the product stream from the total mass of the raw materials. The remainder, 590.98 kg, is the amount of water that goes to "other things." Converting this to liters, we get 591 L/d, which is the same result you obtained.

It is possible that the question may seem simple because it is an introductory question and the calculations involved are straightforward. However, it is important to always double check your work and make sure you understand the concepts behind the calculations. Great job on your solution!