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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: b0gummy on April 30, 2016, 10:57:01 PM

Title: How many moles of potassium are there in 40g of potassium arsenate?
Post by: b0gummy on April 30, 2016, 10:57:01 PM

How many moles of potassium are there in 40g of potassium arsenate?

What I have done so far

Molar Mass of Potassium Arsenate (K₃AsO₄) = 256.2165
Mass of Potassium Arsenate (K3AsO4) = 40g
Number of Moles of (K3AsO4) = 40g/256.2165 (=0.1561 mol)

Not entirely sure of how to get from 0.1561 mol to the number of moles of potassium in 40g of potassium arsenate. Help?

Title: Re: How many moles of potassium are there in 40g of potassium arsenate?
Post by: b0gummy on April 30, 2016, 11:11:18 PM

Nevermind, I have solved this problem. I used ratios to solve for it.

3 mol K/1 mol K3AsO4 = x mol K/0.1561 mol AsO4