What is the mass of $6.12 \times 10^{21}$ $6.12xx10^21$ molecules of $HCl$ $"HCl"$ ?

Question

3016 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-12-07T16:43:08

0.359 grams to three significant figures.

One mole of molecules = $6.02 \times 10^{23}$ $6.02 xx 10^23$ particles.

$\frac{6.12 \times 10^{21}}{6.02 \times 10^{23}} = 1.02 \times 10^{- 2}$ $(6.12 xx 10^21)/ (6.02 xx 10^23 )= 1.02 xx 10^-2$ 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

$36.5 g \times 1.02 \times 10^{- 2} = 0.372$ $36.5 "g" xx 1.02xx 10^-2 = 0.372$ grams

What is the mass of 6.12×10216.12xx10^21 molecules of HCl"HCl"?