To obtain copper from copper oxide, hydrogen was used, obtained by dissolving 140 g of iron in hydrochloric acid.

To obtain copper from copper oxide, hydrogen was used, obtained by dissolving 140 g of iron in hydrochloric acid. How much copper did you get?

To solve this problem, we write down the given: m (Fe) = 140 g
Find: m (Cu) -?
Decision:
Let us write the equation for the reaction of the interaction of iron with hydrochloric acid.
Fe + HCl = FeCl2 + H2
Let’s arrange the coefficients.
Fe + 2HCl = FeCl2 + H2
Let’s calculate the molar mass of iron and hydrogen.
M (Fe) = 56 g / mol
M (H2) = 1 * 2 = 2 g / mol
Over hydrogen we write x g, under hydrogen – 2 g.
Over the iron we write 140 g, and under the iron – 56 g.
Let’s compose and solve the proportion.
x = 140 * 2/56 = 5 g
Let’s compose the reaction equation for obtaining copper from copper (II) oxide.
CuO + H2 = Cu + H2O
We write 5 g over hydrogen, 2 g under hydrogen.
We write y g above the copper, and 64 g below the copper.
Let’s compose and solve the proportion.
y = 5 * 64/2 = 160 g
Answer: 160 g