Chemistry Forum

Hello peeps.

How should I calculate a yield based on weight?

Lets say I have put in 25g of Na₂WO₄, mixed it up with H₃PO₄ and crashed out the compound with KCl.

Compounds formula K₆[P₂W₁₈O₆₄]. Yield = 7g

I want to calculate yield based on the weight of W.

Thanks in advance.

Calculate: m of your product divided by molar mass of the product gives the moles.
The mass of tungsten is then calculated: moles multiplied by the molar mass of tungsten times 18

7g /M(K₆[P₂W₁₈O₆₄]) = x g /(18* M(W))

Thanks for the quick reply.

So I calculated 7g/M(K₆[P₂W₁₈O₆₄]) = 0.0015 mol
18*M(W) = 3311.11 g/mol

Then x = 0.0015 mol * 3311.11 g/mol = 4.96g

As I understand x is W weight in my product mixture. How do I calculate the yield percentage now?

Is it m(W product mixture) / m(W in 25g of Na₂WO₄) * 100% ?

No you have to calculate the m of W in Na₂WO₄ first.

Then you divide this value by the m of W of your product.