You have 15 grams of sodium how many moles of sodium do you have? How many moles of sodium chloride can you produce? How many grams of NaCl can you produce from sodium?

Question

I need a example to help me out so I can understand how to do this

Answer 1

Use the atomic weight of the element or substance to help you get the right units:

Na or sodium atomic weight: 22.989769g/mol

15g x 1mol/22.989769g, notice how the atomic weight is written in inverse or reciprocal. This is to get the units to cancel top to bottom.

Now you have 15g x 1mol/22.989769g = 0.65246 mol of sodium, Na.

To know how many moles of Sodium can be produced, first write the balanced equation:

Na + Cl2 ==> NaCl

.since Cl2 is diatomic, it needs to be accounted for. So to balance:

2Na + Cl2 ==> 2NaCl

From 15 g of Na you got 0.65246 mol. If you use this balanced equation, you can figure out what this means for moles of NaCl and therefore how many grams of NaCl.

If 2Na ==> 2NaCl

0.65246Na==> XNaCl

Cross multiply divide and solve for X

2X = 2*0.65246

X = 2*0.65246/2

X= 0.65246,. So you will have the same amount of moles for NaCl based on the balanced equation. Now to figure out how many grams this is, use the atomic weight of NaCl

NaCl atomic weight: 58.44g/mol

0.65246 mol*58.44g/mol, moles cancel top to bottom and you have:

38.13g or 38 g for sig purposes.