According to the reaction equation Ba + O2 → BaO, calculate the volume of oxygen if 137 g

According to the reaction equation Ba + O2 → BaO, calculate the volume of oxygen if 137 g of barium has entered into a reaction with oxygen.

Given:
m (Ba) = 137 g

To find:
V (O2) -?

Decision:
1) Write the equation of a chemical reaction:
2Вa + О2 => 2ВаО;
2) Calculate the molar mass of Ba:
M (Ba) = Mr (Ba) = Ar (Ba) = 137 g / mol;
3) Calculate the amount of substance Ba:
n (Ba) = m (Ba) / M (Ba) = 137/137 = 1 mol;
4) Determine the amount of substance O2 (taking into account the coefficients in the reaction equation):
n (O2) = n (Ba) / 2 = 0.5 mol;
5) Calculate the volume of O2 (under normal conditions):
V (O2) = n (O2) * Vm = 0.5 * 22.4 = 11.2 liters.

Answer: The volume of O2 is 11.2 liters.