How many moles of compound are there in 4.5 kg #Ca(OH)_2#?

1 Answer
Feb 8, 2016

Answer:

#"4.5 kg Ca(OH)"_2"# contains #"61 moles"#.

Explanation:

Determine Moles of Calcium Hydoroxide

You will need to divide the given mass by the molar mass of #"Ca(OH)"_2"#.

The molar mass of calcium hydroxide, #"Ca(OH)"_2"# is #"74.09268 g/mol"#. https://pubchem.ncbi.nlm.nih.gov/compound/6093208

Since molar mass is given in g/mol, 4.5 kg needs to be converted to grams.

Convert kg to grams.

#4.5cancel"kg"xx(1000"g")/(1cancel"kg")="4500 g"#

Determine the moles of calcium hydroxide contained in #"4500 g Ca(OH)"_2"# by dividing the given mass by its molar mass.

#4500cancel"g Ca(OH)"_2xx(1"mol Ca(OH)"_2)/(74.09268 cancel"g Ca(OH)"_2)="61 mol Ca(OH)"_2"# (rounded to two significant figures)