Under the action of an excess of concentrated nitric acid on 18 g of copper, gas is released. Determine its volume.

| September 8, 2021 | education

Given:

m (HNO3) = 18 g.

V (gas) -?

Solution:

Let’s find the amount of copper substance by the formula:

n = m: M.

M (Cu) = 64 g / mol.

n = 18 g: 64 g / mol = 0.28 mol.

Let’s compose the reaction equation, find the quantitative ratios of substances.

Сu + 4HNO3 = Cu (NO3) 2 + 2NO2 ↑ + H2O

According to the reaction equation, for 1 mol of copper there is 2 mol of gas – nitrogen oxide (IV). The substances are in quantitative ratios of 1: 2.

The amount of gas substance will be 2 times more than the amount of copper substance.

n (Cu) = n (NO2) = 0.28 × 2 = 0.56 mol.

Let’s find the volume of gas by the formula:

V = Vn n, where Vn is the molar volume of gas, equal to 22.4 l / mol, and n is the amount of substance.

V = 22.4 L / mol × 0.56 mol = 12.54 L.

Answer: V = 12.54 liters.



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