In the reaction between aluminum and hydrochloric acid, how many moles of hydrogen gas would be liberated when 3.612E-2 grams of aluminum are treated with excess hydrochloric acid?
Moles of hydrogen gas liberated = mol
The atmospheric pressure was measured to be 0.9666 atm and the room temperature was 25.00oC. At this temperature, the vapor pressure of water is 23.80 torr. What would be the volume of the number of moles of hydrogen just calculated under these conditions? Enter the answer in mL.
Volume of hydrogen gas = mL
The syringe used in this experiment is calibrated to 60 mL. However, there is a 'dead volume' at the needle end of the syringe that is uncalibrated. This volume equals 1.20 mL. Bearing in mind that the syringe is upside down, what would the reading on the syringe be that corresponded to the volume you have just calculated?
Reading on the syringe = mL
Suppose that you have completed this week's experiment and have determined that the molar mass of aluminum is 24.80 g mol-1. What is the percent error of your experimental result?
Percent error of the experimental result = %
2Al + 6HCl ==> 3H2 + 2AlCl3
3.612E-2g Al/molar mass Al = moles Al.
Convert moles Al to moles H2 by
?mols Al x (3 moles H2/2 moles Al) = ? mols Al x (3/2) = x moles H2.
PV = nRT
P = 0.9666 atm - v.p. H2O @ 25C.
v. p. H2O = 23.80mm/760 = xx
V = ?
R = 0.08206 L*atm/mol*K
T = 25.00 converedt to K.
I don't understand about the syringe.
%error = [(23.80-atomic mass Al)/atomic mass Al]*100 = ?
To find the moles of hydrogen gas liberated in the reaction between aluminum and hydrochloric acid, we need to determine the number of moles of aluminum used.
Step 1: Convert the mass of aluminum to moles.
Given that the mass of aluminum is 3.612E-2 grams, we can use the molar mass of aluminum to convert it to moles.
The molar mass of aluminum is given as 24.80 g mol-1.
Using the formula:
moles = mass / molar mass
moles = 3.612E-2 g / 24.80 g mol-1
moles = 0.001457 mol (rounded to 4 decimal places)
Step 2: Use the balanced equation to determine the moles of hydrogen gas released.
The balanced equation for the reaction between aluminum and hydrochloric acid is:
2Al + 6HCl → 2AlCl3 + 3H2
From the equation, we can see that 2 moles of aluminum will produce 3 moles of hydrogen gas.
Therefore, the number of moles of hydrogen gas liberated would be:
moles of hydrogen gas = (moles of aluminum) * (3 moles of H2 / 2 moles of Al)
moles of hydrogen gas = 0.001457 mol * (3 mol H2 / 2 mol Al)
moles of hydrogen gas = 0.0021855 mol (rounded to 4 decimal places)
So, the moles of hydrogen gas liberated would be 0.0022 mol.
To find the volume of hydrogen gas under the given conditions, we need to use the ideal gas law equation:
PV = nRT
Step 1: Convert atmospheric pressure from atm to torr.
Given the atmospheric pressure as 0.9666 atm, we need to convert it to torr.
1 atm = 760 torr
0.9666 atm = 0.9666 * 760 torr = 734.616 torr
Step 2: Convert room temperature from degrees Celsius to Kelvin.
Given the room temperature as 25.00 degrees Celsius, we need to convert it to Kelvin.
Kelvin = Celsius + 273.15
Kelvin = 25.00 + 273.15 = 298.15 K
Step 3: Calculate the partial pressure of hydrogen gas.
The vapor pressure of water is given as 23.80 torr.
Since the reaction between aluminum and hydrochloric acid produces hydrogen gas and water, the partial pressure of hydrogen gas is:
partial pressure of hydrogen gas = total pressure - vapor pressure of water
partial pressure of hydrogen gas = 734.616 torr - 23.80 torr = 710.816 torr
Step 4: Calculate the volume of hydrogen gas.
Using the ideal gas law equation:
PV = nRT
V = (nRT) / P
V = (0.0022 mol * 0.0821 L atm mol-1 K-1 * 298.15 K) / (710.816 torr / 760 torr/atm)
V = (0.181153 L atm mol-1) / 0.94063
V = 0.192653 L (rounded to 6 decimal places)
To convert the volume from liters to milliliters, multiply the volume by 1000:
Volume of hydrogen gas = 0.192653 L * 1000 = 192.653 mL (rounded to 3 decimal places)
Considering the dead volume at the needle end of the syringe, we need to subtract it from the calculated volume to get the reading on the syringe.
Reading on the syringe = Volume of hydrogen gas - Dead volume
Reading on the syringe = 192.653 mL - 1.20 mL
Reading on the syringe = 191.453 mL (rounded to 3 decimal places)
Finally, to calculate the percent error of the experimental result:
Step 1: Calculate the theoretical value of moles of hydrogen gas using stoichiometry.
From the balanced equation, we know that 2 moles of aluminum produce 3 moles of hydrogen gas.
Thus, if we assumed that all the aluminum reacted and calculated the moles of hydrogen gas using the moles of aluminum (0.001457 mol), the theoretical value would be:
moles of hydrogen gas (theoretical value) = 0.001457 mol * (3 mol H2 / 2 mol Al)
moles of hydrogen gas (theoretical value) = 0.0021865 mol (rounded to 4 decimal places)
Step 2: Calculate the percent error.
Percent error = ((Experimental value - Theoretical value) / Theoretical value) * 100
Percent error = ((0.0022 mol - 0.0021865 mol) / 0.0021865 mol) * 100
Percent error = (0.0000135 mol / 0.0021865 mol) * 100
Percent error = 0.617% (rounded to 3 decimal places)
Therefore, the percent error of the experimental result is 0.617%.