Question

Карбид алюминия обработан 200 г 30% раствора серной кислоты. Выделившийся при этом метан занял объём 4,48 л (н.у). Рассчитать массовую долю серной кислоты в полученном растворе.

Answer 1

Уравнение реакции :AL4C3 +6H2SO4----->3CH4+2AL2(SO4)3
1.Найдем исходное количество молей кислоты :
n(h2SO4)=m*w/M=200 г *0,3/98г/моль=0,612 моль
2.Найдем массу метана :
m(CH4)=n*M=0,2 моль*16г/моль=3,2 г
3.Масса карбида алюминия равна :
m(AL4C3)=1/3*n(CH4)*144=9,6 г
4.Масса раствора :
m(р-ра)=200 г + 9,6 г -3,2 г=206,4 г
5.Количество молей метана : n(CH4)=2*n(CH4)=0,2*2=0,4 моль
6.Остаток кислоты : 0,612 моль-0,4 моль=0,212 моль
Тогда,массовая доля серной кислоты в полученном растворе равна :
w(H2SO4)=0,212 моль * 98 г/моль/206,4*100=10,065=10,1%

Answer 2

Calculation of the Mass Fraction of Sulfuric Acid in the Solution

To calculate the mass fraction of sulfuric acid in the obtained solution, we need to use the given information about the amount of aluminum carbide and the volume of methane produced.

The equation for the reaction between aluminum carbide (Al4C3) and sulfuric acid (H2SO4) is as follows:

Al4C3 + 12H2SO4 → 4Al(SO4)3 + 3CH4

From the given information, we know that 200 g of aluminum carbide was treated with a 30% solution of sulfuric acid, and 4.48 L of methane gas was produced at standard temperature and pressure (n.u).

To calculate the mass fraction of sulfuric acid in the solution, we can use the stoichiometry of the reaction. The molar ratio between aluminum carbide and sulfuric acid is 1:12. This means that for every 1 mole of aluminum carbide, 12 moles of sulfuric acid are required.

To find the moles of aluminum carbide, we can use its molar mass. The molar mass of aluminum carbide (Al4C3) is calculated as follows:

4(Al) + 3(C) = 4(26.98 g/mol) + 3(12.01 g/mol) = 144.02 g/mol

Using the given mass of aluminum carbide (200 g) and its molar mass, we can calculate the moles of aluminum carbide:

moles of Al4C3 = mass of Al4C3 / molar mass of Al4C3 = 200 g / 144.02 g/mol

Now, we can use the stoichiometry of the reaction to find the moles of sulfuric acid:

moles of H2SO4 = moles of Al4C3 × 12

Next, we need to calculate the mass of sulfuric acid in the solution. The mass of sulfuric acid can be calculated using its molar mass, which is 98.09 g/mol.

mass of H2SO4 = moles of H2SO4 × molar mass of H2SO4

Finally, we can calculate the mass fraction of sulfuric acid in the solution:

mass fraction of H2SO4 = mass of H2SO4 / (mass of H2SO4 + mass of water)

Unfortunately, the given information does not provide the mass of water in the solution. Without this information, it is not possible to calculate the mass fraction of sulfuric acid accurately.

Please provide the mass of water in the solution so that we can proceed with the calculation.