Question

Какой объем водорода н.у образуется при взаимодействии 650 мг цинка содержащего 20% примесей с необходимым количеством HCI? какое количество вещества газа водорода при этом получится?

Answer 1

Zn+2HCI=ZnCI2+H2
M(Zn)=65г/моль
650мг.=0,65гр.
0,65гр это100%
х----------80%
х=0,65*80/100=0,52г.
n(Zn)=m/M=0,52/65=0,008моль
nZn=n(H2)=0,008моль
V(H2)=0,008*22,4=0,18л
Колличество вещества n(H2)=0,008моль

Answer 2

Calculation of Hydrogen Gas Volume

To calculate the volume of hydrogen gas formed when 650 mg of zinc, containing 20% impurities, reacts with the necessary amount of hydrochloric acid (HCl), we need to use the concept of stoichiometry.

The balanced chemical equation for the reaction between zinc and hydrochloric acid is:

Zn + 2HCl → ZnCl2 + H2

From this equation, we can see that 1 mole of zinc reacts with 2 moles of hydrochloric acid to produce 1 mole of hydrogen gas.

To determine the number of moles of zinc, we need to convert the mass of zinc to moles. The molar mass of zinc (Zn) is approximately 65.38 g/mol Therefore, the number of moles of zinc can be calculated as follows:

Number of moles of zinc = mass of zinc / molar mass of zinc

Given that the mass of zinc is 650 mg (or 0.65 g) and the zinc contains 20% impurities, we need to consider only the pure zinc content. Therefore, the mass of pure zinc can be calculated as follows:

Mass of pure zinc = mass of zinc × (1 - impurity percentage)

Substituting the values, we have:

Mass of pure zinc = 0.65 g × (1 - 0.20) = 0.52 g

Now we can calculate the number of moles of zinc:

Number of moles of zinc = 0.52 g / 65.38 g/mol

Next, we need to determine the number of moles of hydrogen gas produced. Since the stoichiometric ratio between zinc and hydrogen gas is 1:1, the number of moles of hydrogen gas will be the same as the number of moles of zinc.

Finally, to calculate the volume of hydrogen gas at standard temperature and pressure (STP), we can use the ideal gas law, which states that 1 mole of any gas occupies 22.4 liters at STP:

Volume of hydrogen gas = Number of moles of hydrogen gas × 22.4 liters/mol

Please note that the above calculation assumes ideal conditions and does not take into account any deviations from the ideal gas law.

Let's calculate the volume of hydrogen gas:

Volume of hydrogen gas = Number of moles of zinc × 22.4 liters/mol

Now, let's substitute the values and calculate the volume of hydrogen gas.