Question

1. Given the following reaction: Na2S2O3 + AgBr NaBr + Na3 (Ag(S2O3)2)
How many moles of Na2S2O3 are needed to react completely with 52.9 g of AgBr?

Answer 1

Answer:

0.28 moles

Explanation:

First, find the number of moles of AgBr.

Number of moles = Given mass/molar mass

You have the given mass (52.9g) what's the molar mass, you can use the periodic table to figure it out.

Ag=107.8g and Br=79.9g, add it up you get 187 roughly.

Now just divide 52.9 by 187.

You get 0.28 moles.

The ratio between Na2S2O3 and AgBr is 1:1

So, 0.28 moles of AgBr is equal to 0.28 moles of Na2S2O3.