chemistry- word problem

Question

The food flavor enhancer monosodium glutamate (MSG) has the composition 13.6% Na, 35.5% C, 4.8% H, 8.3% N, 37.8% O, by mass. 


What is the empirical formula of MSG?

Express your answer as a chemical formula.

Answer 1

Hi Amy,

 

Assume you have 1g of your sample.

 

Then 13.6% of this sample is Na, that is 0.136g.

Since you are to find the empirical formula, you need to find the number of moles of Na in 0.136g. You can do that by dividing by the atomic mass of Na: n(Na)=0.136g / 23.0 g/mol = 0.00591 mol

 

Next, you repeat this for all the other elements.

 

The last step is to pick the smallest number of moles that you get and divide the others by it. That way you should arrive at whole number coefficients for the empirical formula. The element with the smallest number of moles gets 1 as its coefficient).

 

Hope this helps!

 

Martin G.