Do you know what is meant by needed? does it mean lone pairs?
The balanced equation for the reaction is as follows
Cu₂O + 2HCl ---> 2CuCl + H₂O
Molar ratio of Cu₂O to CuCl is 1:2
mass of Cu₂O reacted - 73.5 g
Number of moles of Cu₂O reacted - 73.5 g / 143 g/mol = 0.51 mol
According to the molar ratio,
when 1 mol of Cu₂O reacts then 2 mol of CuCl is formed
therefore when 0.51 mol of Cu₂O reacts then - 2 x 0.51 mol of CuCl is formed
number of CuCl moles formed - 1.02 mol
mass of CuCl formed - 1.02 mol x 99 g/mol = 101 g
mass of CuCl formed is 101 g
It is because say water boils at 212 F, if it goes higher at 213 it would get so much heat and energy it turns into a gas, so it cannot stay a liquid with 213 because at that point it would be gas, thus when water reaches 212 it's max if it goes any higher it will be gas
