for 2Na (s) + Cl2 (g) - >2NaCl (s) how many grams of sodium chloride will be made from 115 g of sodium metal when when reacted with excess chlorine gas

The grams of sodium chloride that will be made is 292.5 g

calculation

2Na + Cl₂ → 2NaCl

step 1: calculate the moles of Na

moles = mass/molar mass

From periodic table the molar mass of Na = 23 g/mol

moles = 115 g/23 g / mol = 5 moles

Step 2 : use the mole ratio to determine the moles of NaCl

Na:NaCl is 2:2 = 1:1 therefore the moles of NaCl is also = 5 moles

Step 3: find the mass of NaCl

mass = moles x molar mass

The molar mass of NaCl = 23 + 35.5 = 58.5 g/mol

mass = 5 moles x 58.5 g/mol = 292.5 g