Question

Из 11,2 л ацетилена получили 8 г бензена. Вычеслите массовую долю выхода бензена

Answer 1

3 C2H2 = C6H6
n(C2H2) = 11.2/22.4 = 0,5 моль
M(C6H6) = 78 г/моль
n(C6H6) = 8/78 = 0,102 моль
Сравнивая n(C2H2) и n(C6H6), то С6H6 в избытке, C2H2 в недостатке
m(C6H6)= 0,5*78 = 39 г
w(C6H6)= 8/39 * 100% = 20,51 %

Answer 2

Calculating the Mass Fraction of Benzene Obtained from 11.2 L of Acetylene

To calculate the mass fraction of benzene obtained from 11.2 L of acetylene, we can use the stoichiometry of the reaction that produces benzene from acetylene.

The balanced chemical equation for the conversion of acetylene to benzene is:

2 C2H2 → C6H6

This equation shows that 2 moles of acetylene (C2H2) produce 1 mole of benzene (C6H6).

Given that the molar mass of acetylene (C2H2) is approximately 26 g/mol and the molar mass of benzene (C6H6) is approximately 78 g/mol, we can calculate the mass fraction of benzene obtained from 11.2 L of acetylene.

Calculation:

1. Calculate the moles of acetylene: - Using the ideal gas law, we can convert the volume of acetylene to moles. - The molar volume of a gas at standard temperature and pressure (STP) is 22.4 L/mol.

Moles of acetylene = Volume of acetylene / Molar volume at STP Moles of acetylene = 11.2 L / 22.4 L/mol Moles of acetylene = 0.5 moles

2. Calculate the moles of benzene produced: - From the balanced chemical equation, 2 moles of acetylene produce 1 mole of benzene.

Moles of benzene = Moles of acetylene / 2 Moles of benzene = 0.5 moles / 2 Moles of benzene = 0.25 moles

3. Calculate the mass of benzene produced: - Using the molar mass of benzene, we can calculate the mass of benzene produced.

Mass of benzene = Moles of benzene * Molar mass of benzene Mass of benzene = 0.25 moles * 78 g/mol Mass of benzene = 19.5 g

4. Calculate the mass fraction of benzene: - The mass fraction of benzene is the mass of benzene produced divided by the total mass of products.

Mass fraction of benzene = Mass of benzene / Total mass of products Mass fraction of benzene = 19.5 g / (19.5 g + mass of other products)

Conclusion:

The mass fraction of benzene obtained from 11.2 L of acetylene is approximately 19.5 g.