Answer to Question #156018 in Inorganic Chemistry for Lia Rodriguez

Question

in which of the following substances there is a greater number of moles?
Ca=40   Na=23    He=4     Mg=24    Li=7

A. 5g of Ca

B. 2g of Na

C. 10g of He

D. 25g of Mg

E. 15g of Li

Answer 1

Mol of a substance = mass of substance \ molar mass of that substance

A. 5 g Ca = 5 g \ 40 g mol-1 = 0.125 mol

B. 2 g Na = 2 g\ 23 g mol-1 =0.07 mol

C. 10 g He = 10 g\4 g mol-1 = 2.5 mol

D. 25 g Mg = 25g\ 24 gmol-1 = 1.04 mol

E. 15 g Li = 15 g\ 7 g mol-1 = 2.14 mol

Greater no of mole for He 2.5 mol ans C