Question

What is the mass of 2.20 moles of magnesium chloride, MgCl2?

How many moles of nitrogen, N, are in 82.0 g of nitrous oxide, N2O?

Answer 1

number of moles of MgCl2= 2.20 moles

molar mass of MgCl2= 95.21 g/mole

number of moles = mass of solute/molar mass

mass of solute = number of moles x molar mass

mass of MgCl2= 2.20x95.21=209.462 g

mass of MgCl2= 209.46 grams.

b)

mass of N2O= 82.0g

molar mass of N2O = 44.0g/mole

number of moles of N2O = mass/molar mass = 82.0/44.0= 1.864 moles

number of moles ofN2O = 1.864 moles

number of moles of Nitrogen = 1.864x2= 3.728 moles

number of moles of Nitrogen atoms= 3.73 moles