Question

How many moles are in 89.9 mg of Ca(OH)2 ? (Report to 4 decimal places, do not write in scientific notation)

Answer 1

The molar mass of Ca(OH)2 is:

Ca = 40.08 g/mol

O = 15.999 g/mol

H = 1.008 g/mol

Molar mass of Ca(OH)2 = (1 x 40.08) + (2 x 15.999) + (2 x 1.008) = 74.096 g/mol

To find the number of moles in 89.9 mg of Ca(OH)2, we can use the formula:

moles = mass / molar mass

moles = 0.0899 g / 74.096 g/mol = 0.0012122 mol

Therefore, there are 0.0012 moles (rounded to 4 decimal places) in 89.9 mg of Ca(OH)2.