Converting 18ct gold 22ct gold?

Question

i have 350.85 g of 69.5% touch gold , i want to convert it 75% gold so much i add pure? send it detail how its converted.

Answer 1

If I understand correctly that you have 350.85 grams of .695 fine gold,

that you want to convert to 18K (.750 fine)

Then there is  350.85 x  .695 = 243.84075 grams of 24K gold in it.

So we set up an equation. g will be the amount of gold that we will add.

(243.84075 + g ) / (350.85 + g ) = .750

The new amount of the pure gold divided by the new total weight must be .750

So fiddling the numbers,

( 243.84075 + g ) = 0.750 x ( 350.85 + g )

243.84075 + g = 263.1375 + .75g

0.25g = 19.29675

g = 77.187 grams

Check:

(243.84075 + 77.187  ) / (350.85 + 77.187  )

321.02775 / 428.037 = 0.75

I want to learn to be a goldsmith!

Answer 2

Wrong category.