Question

Hydrogen produced from a hydrolysis reaction was collected over water. The data is compiled in the table.

Total volume of H2(g) collected 94.00 mL

Temperature 26.0 °C

Barometric pressure 745 mmHg

Vapor pressure of water at 26.0 °
25.5 mmHg

Calculate the moles of hydrogen gas produced by the reaction.

moles:

Answer 1

To calculate the moles of hydrogen gas produced, we need to use the ideal gas law equation:

PV = nRT

where P is the total pressure, V is the volume of the gas, n is the number of moles of gas, R is the gas constant, and T is the temperature in Kelvin.

First, we need to convert the temperature to Kelvin by adding 273.15:

T = 26.0 + 273.15 = 299.15 K

Next, we need to calculate the pressure of the hydrogen gas by subtracting the vapor pressure of water from the barometric pressure:

P(H2) = P(total) - P(vapor) = 745 - 25.5 = 719.5 mmHg

Now we can plug in the values into the ideal gas law equation and solve for n:

n = PV/RT

n = (719.5 mmHg)(94.00 mL)/(62.3637 L mmHg/K mol)(299.15 K)

n = 0.00384 mol

Therefore, the moles of hydrogen gas produced by the reaction is 0.00384 mol.