Question

What mass of calcium hydroxide is formed when 10.0g of calcium oxide reacts with 10.0g of water?

Answer 1

The mass of calcium hydroxide that is formed when 10.0 g of CaO reacts with  10.0 g of water is 13.024 grams

calculation

from the equation

CaO + H2O → Ca(OH)2,

 1 moles of CaO reacted with 1 moles of H2O to form 1 moles of Ca(OH)2

find the moles of each reactant

moles=mass/molar mass

moles of CaO= 10 g/56 g/mol=0.179 moles

moles of H2O = 10 g/18 g/mol 0.556  moles

CaO is the limiting reagent  therefore by use of mole ratio of CaO:Ca(OH)2 which is 1:1 moles of Ca(OH)2 is = 0.179 moles

mass= moles x molar mass

= 0.176 moles x  74 g/mol = 13.024  grams