chemistry gNa answer...

Question

A  14.43g sample of NaBr contains % Na by mass. Considering the law of constant composition (definite proportions), how many grams of sodium does a  7.93g sample of sodium bromide contain?

Answer 1

Hello, and thank you for your question.

I believe there is missing information on your question, but I believe I can still help you answering it.

So, we have a sample of NaBr, that weighs 7.93 grams. We would like to know how much sodium there is in this sample, in grams.

We start by converting the initial sample from grams to moles of the compound. using the molar mass of NaBr. After that, we want to make a mol to mol convertion, from NaBr to Na, which is a 1:1 ratio. Lastly, once we get that number, we convert it to grams, using the atomic mass of sodium in the periodic table.

It looks like this:

7.93g NaBr x ( 1mol NaBr / 102.894g NaBr) x ( 1molNa / 1mol NaBr) x ( 22.99g Na / 1mol Na). This will give us 1.772 grams of Sodium present in 7.93 grams of NaBr,

Hope this helps :)