Answer:
Molar mass of Ca = 40 g / mol , given 123 g Ca is 123/40= 3.075 moles,
1 mole = 6.022 * 10^23 atoms, so 3.075 moles Ca= 18.51*10^23 atoms
Explanation:
Since we already have the balanced equation, we know that the ratio between
is
respectively.
So then we can set up a proportion to find the number of moles produced when 2.90 moles of Na react completely:

Then we cross multiply and solve for x:


Therefore, we know that when 2.90 moles of Na react completely, there are 1.45 moles of
that are produced.
276 grams of carbon in 23.0 moles