What is the mass of #6.12xx10^21# molecules of #"HCl"#?

1 Answer

Answer:

0.359 grams to three significant figures.

Explanation:

One mole of molecules = # 6.02 xx 10^23# particles.

# (6.12 xx 10^21)/ (6.02 xx 10^23 )= 1.02 xx 10^-2# moles

One mole of HCl Hydrochloric acid = 36.5 grams

1 H = 1 xx 1.00 gram/mole = 1.00 grams

1 Cl = 1 xx 35.45 grams/mole = 35.5 grams ( to 3 sig numbers)

1.00 + 35.5 = 36.5 grams/ moles

# 36.5 "g" xx 1.02xx 10^-2 = 0.372 # grams