If the water temperature was 30.0C and the atmospheric pressure was 753 torr. What volume of hydrogen gas would you expect to collect if you reacted 0.083g of Ca metal with HCl?
Ca + 2HCl ==> H2 + CaCl2
mols Ca = grams/molar mass = ?
mols H2 = mols Ca from the equation.
Then use PV = nRT and
V = nRT/P. You know n, R, T. P is 753- vapor pressure H2O at 30 C. You look up v.p. H2O at 30 C in tables in your test. It will be approximately 30 torr.
.053
To find the volume of hydrogen gas produced when reacting calcium (Ca) metal with hydrochloric acid (HCl), we need to follow a few steps.
Step 1: Determine the balanced chemical equation:
The balanced chemical equation for the reaction between Ca and HCl is:
Ca + 2HCl -> CaCl2 + H2
This equation tells us that for every 1 mole of Ca, 2 moles of HCl are required to produce 1 mole of H2 gas.
Step 2: Calculate the moles of Ca:
To calculate the moles of Ca, we need to use its molar mass. The molar mass of Ca is approximately 40.08 g/mol.
Given that we have 0.083 g of Ca, we can use the following formula to calculate the moles:
moles = mass/molar mass
moles = 0.083 g / 40.08 g/mol
moles ≈ 0.00207 mol
Step 3: Calculate the moles of H2:
Since the reaction is 1:1 between Ca and H2, the moles of H2 produced will be the same as the moles of Ca, which is approximately 0.00207 mol.
Step 4: Calculate the volume of H2 gas at the given conditions:
To calculate the volume of H2 gas, we can use the ideal gas law equation:
PV = nRT
P = atmospheric pressure = 753 torr
V = volume of H2 gas (unknown)
n = moles of H2 gas = 0.00207 mol
R = ideal gas constant = 0.0821 L × atm/(mol × K)
T = temperature in Kelvin (K) = Celsius temperature + 273
Given that the water temperature is 30.0°C, we convert it to Kelvin by adding 273:
T = 30.0°C + 273 = 303 K
Now we can solve the ideal gas law equation for the volume (V):
V = (nRT) / P
V = (0.00207 mol × 0.0821 L × atm/(mol × K) × 303 K) / 753 torr
Step 5: Convert the volume to the desired units:
The given volume is in torr, but we typically use units like liters (L). To convert torr to liters, we need to use the following conversion factor:
1 L = 760 torr
V = [(0.00207 mol × 0.0821 L × atm/(mol × K) × 303 K) / 753 torr] × (1 L / 760 torr)
V ≈ 0.00161 L
Therefore, the expected volume of hydrogen gas collected is approximately 0.00161 L.