Question

Calculate mass in grams :

0.755 mol zinc chloride

0.203 μmol potassium chlorate

0.424 mmol POCl₃

4.32 × 10^-3 mol (NH₄)₂HPO₄

0.789 mol S

3.99 mol N

4.86 mol Al

Answer 1

0.755 mol zinc chloride

mass of ZnCl2   = no of moles of ZnCl2 * gram molar mass of ZnCl2

                          = 0.755*136   = 102.68g

0.203 μmol potassium chlorate

0.203*10^-6 mole K2CrO4

mass of K2CrO4   = no of moles of K2CrO4 * gram molar mass of K2CrO4

                             = 0.203*10^-6 * 194   = 3.94*10^-5 g

0.424 mmol POCl₃

0.424mmole = 0.424*10^-3 moles

mass of POCl3   = no of moles of POCl3 * gram molar mass of POCl3

                          = 0.424*10^-3 * 153   = 0.0649 g

4.32 × 10^-3 mol (NH₄)₂HPO₄

mass of (NH₄)₂HPO₄    = no of moles of (NH₄)₂HPO₄ * gram molar mass of (NH₄)₂HPO₄

                                      = 4.32*10^-3 * 132   = 0.57g

0.789 mol S

mass of S = no of moles of S * gram atomic mass of S

                   = 0.789*32   = 25.25g

3.99 mol N

mass of N = no of moles of N * gram atomic mass of N

                  = 3.99*14   = 55.86g

4.86 mol Al

mass of Al   = no of moles of Al * gram atomic mass of Al

                  = 4.86 * 27 = 131.22g