Calculate the mass of copper oxide formed during the decomposition of 98 g of copper hydroxide.

Let’s write down the solution, compose an equation according to the condition of the problem:
Cu (OH) 2 = CuO + H2O – the decomposition reaction of copper hydroxide occurs when heated, copper oxide is formed;
Let’s make calculations using the formulas:
MCu (OH) 2 = 97.5 g / mol;
M (CuO) = 79.5 g / mol.
Determine the amount of mol of copper hydroxide, if the mass is known:
YCu (OH) 2 = m / M = 98 / 97.5 = 1.005 mol;
According to the equation, the amount of moles of copper hydroxide and copper oxide is equal to 1 mole, which means that Y (CuO) = 1.005 mole.
Find the mass of copper oxide:
m (CuO) = Y * M = 1.005 * 79.5 = 79.89 g.
Answer: the mass of copper oxide is 79.89 g.