Keeping track of information with a table

One thousand kilograms per hour of a mixture containing equal parts by mass of ethanol and water is distilled. Product streams leave the top and the bottom of the distillation column. The flowrate of the bottom stream is measured and found to be 673 kg/h, and the overhead stream is analyzed and found to contain 96 wt% ethanol. Find the flowrates of all components in all streams.

We can write this equation:

F_{feed, ethanol} = F_{feed total} x_{feed, ethanol}

We can write this because we were told that there were equal parts of ethanol and water by bass in the stream to be distilled. So, x_{feed, ethanol} = x_{feed, water} = 0.5

Actually, then, F_{feed, ethanol} = F_{feed, water} = 1000 * 0.5 = 500

Let's fill both of those values into the table:

Streams\mass flow rate	Total	Ethanol	Water
Feed	1000	500	500
Overhead	F_{overhead,total}	F_{overhead,ethanol}	F_{overhead,water}
Bottoms	673	F_{bottoms,ethanol}	F_{bottoms,water}

Now that we've filled that information in, what do you think we can do next?