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.

Answer 1

To calculate the moles of hydrogen gas produced by the reaction, you can use the Ideal Gas Law: PV = nRT, where P is pressure, V is volume, n is the number of moles, R is the gas constant, and T is temperature in kelvin.

First, convert the temperature to kelvin:

T = 26.0 °C + 273.15 = 299.15 K

Next, calculate the pressure of the hydrogen gas by subtracting the vapor pressure of water from the total pressure:

P = 745 mmHg - 25.5 mmHg = 719.5 mmHg

Now convert the pressure units to atmospheres:

P = 719.5 mmHg * (1 atm / 760 mmHg) = 0.947 atm

Finally, convert the volume to liters:

V = 94.00 mL * (1 L / 1000 mL) = 0.094 L

Now we can calculate the number of moles of hydrogen gas:

n = PV / RT
n = (0.947 atm * 0.094 L) / (0.0821 Latm/molK * 299.15 K)
n = 0.0106 mol

So, 0.0106 moles of hydrogen gas were produced by the reaction