a 4.22 gram sample of copper II sulfide was added to excess hydrocholoric acid with hydrogen sulfide gas being generated and collected over water. What volume of hydrogen sulfide gas would be collected at 32 degrees Celcius and 749 torr? The vapor pressure of water at 32 degrees 36 torr.
Write and balance the equation.
CuS + 2HCl --> H2S + CuCl2
Convert 4.22 g CuS to mols. Remember mols = g/molar mass.
Convert mols CuS to mols H2S.
Use PV = nRT to calculate volume at the conditions listed.
Post your work if you get stuck.
Note the correct spelling of Celsius.
1.18 L
To find the volume of hydrogen sulfide gas collected, we can use the ideal gas law equation:
PV = nRT
Where:
P = pressure
V = volume
n = number of moles
R = ideal gas constant
T = temperature in Kelvin
First, let's convert the given temperature from Celsius to Kelvin:
T(K) = T(C) + 273.15
T(K) = 32 + 273.15
T(K) = 305.15 K
Now, let's calculate the pressure of the collected hydrogen sulfide gas:
P(total) = P(H2S) + P(water)
P(total) - P(water) = P(H2S)
P(H2S) = P(total) - P(water)
P(H2S) = 749 torr - 36 torr
P(H2S) = 713 torr
Next, we need to determine the number of moles of hydrogen sulfide gas produced. To do this, we need to use stoichiometry.
The balanced chemical equation for the reaction is:
CuS + 2HCl -> CuCl2 + H2S
From the equation, we can see that 1 mole of copper II sulfide (CuS) produces 1 mole of hydrogen sulfide (H2S).
The molar mass of CuS is approximately 95.612 g/mol (63.546 g/mol for copper + 32.066 g/mol for sulfur).
Using the given mass of the copper II sulfide sample (4.22 grams), we can calculate the number of moles:
n(CuS) = mass / molar mass
n(CuS) = 4.22 g / 95.612 g/mol
n(CuS) ≈ 0.0442 mol
Therefore, the number of moles of hydrogen sulfide (H2S) produced is also 0.0442 mol.
Now, we can use the ideal gas law equation to find the volume of hydrogen sulfide gas:
PV = nRT
V = (nRT) / P
V = (0.0442 mol * 0.0821 L·atm/(mol·K) * 305.15 K) / 713 torr
Note: The ideal gas constant, R, is 0.0821 L·atm/(mol·K).
Converting torr to atm:
1 atm = 760 torr
V ≈ (0.0442 mol * 0.0821 L·atm/(mol·K) * 305.15 K) / (713 torr * (1 atm/760 torr))
V ≈ 0.446 L
Therefore, approximately 0.446 liters of hydrogen sulfide gas would be collected.