3) calculate the mass of 0.750 mole of c2h6o.
4) how many formula units are there in 5.4 g of nacl?
5) how many moles are there in 50.0 g of caco3?

(3) 34.5grammes of C2H6O

(4) 5.56 x 10^22 Formula units

(5) 0.5 moles of CaCO3

Explanation:

(3) molar mass of C2H6O = 24 + 6 + 16 = 46 g/mol

mass of C2H6O =0.75 mole x 46 g/mole = 34.5 grammes

(4) Formula units of NaCl = (5.4/ 58.5) x 6.022x10^23 = 5.56 x 10^22

(4) moles = mass / molar mass

molar mass of CaCO3 = 40 + 12 + 48 = 100 g/mol

moles of CaCO3 = 50/100 = 0.5 moles

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