Question

How many grams silver is added to 13 grams gold to produce 85% gold alloy?

Answer 1

I assume the percent you want is w/w.
(grams solute/grams solution)*100 = % w/w
[(x)/(x+13)]*100 = 85
Solve for x

Answer 2

I tried that formula. I guess it's wrong :(

Answer 3

Sorry. I gave you the correct formula; however, I substituted Ag for Au which determine 85% Ag in Au. For 85% Au you want the same formula but substitute 13 for solute (Au) and x+13 (grams solution) for the solution
[(grams solute)/(grams solution)]*100 = 85
[13/(x+13)]*100 = 85
Solve for x = grams Ag. I would plug that back into the equation to see that it is 85%.

Answer 4

sir, when I used the first formula, I get 73.7g. Ag is that correct? or there's something wrong with my calculation?

Answer 5

when I used the second formula I get g.Au? :(

Answer 6

Your answer is right. Try to check it. [73.7/(73.7+13)]*100=85