question_answer

  Verify by calculating that (a) 5 moles of  and 5 moles of  do not have the same mass. (b) 240 g of calcium and 240 g of magnesium elements have a mole ratio of 3:5.

Answer:

                  (a) has molar mass = 44 g mol-1 5 moles of have molar mass = 44 x 5 == 220 g has molar mass = 18 g mol-1 5 moles of  have mass = 18 x 5g = 90g (b) Number of moles in 240 s Ca metal  Number of moles in 240 s of Ms metal Ratio                      6 : 10 or,                          3 : 5