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

The way to convert between grams and moles is to use molar mass. The molar masses of single elements, like sodium, can be found by looking at a periodic table. The molar of compounds can be calculated by adding up the molar masses of the individual atoms in the compound.

To convert 15 g of sodium we get the molar mass of sodium (Na) from the periodic table. It is 22.99 g/mol. This says that every 1 mole of sodium has a mass of 22.99 g. If we have 15 g then we have:

15 g x 1 mol/22.99 g = 15/22.99 mol

= 0.65 mol

If you want to produce NaCl from this, you need an equal number of moles of Cl. This is because in each molecule of NaCl, there is one Na atom and one Cl atom, thus the ratio of Na to Cl is 1-to-1. In short, if you have 0.65 mol of Na, then you would need 0.65 mol of Cl to make 0.65 mol of NaCl. To get the number of grams of this much NaCl, we need to use the molar mass of NaCl which is:

22.99 g/mol (molar mass of Na) + 35.45 g/mol (molar mass of Cl) = 58.44 g/mol

This says that there are 58.44 g for every 1 mol of NaCl. We have 0.65 mol of NaCl though, so we multiply this by the molar mass of NaCl to get

0.65 mol x 58.44 g/mol = 38 g

In summary, if we have 15 g of sodium, and assuming we have enough chloride, we can make 38 g of NaCl.