calculate the volume of hydrogen produced from .025g of aluminum and sufficient HCl at 21 degrees Celsius and 755 torr according to the following reaction:
Al(s) + HCl(aq)--------- AlCl3 (aq) + H2(g)
Volume of H2________ml
2Al + 6HCl ==> 2AlCl3 + 3H2
mols Al = grams/molar mass
Using the coefficients in the balanced equation, convert mols Al to mols H2.
Then use PV = nRT and convert mols H2 to L at the conditions listed. Change L to mL.
To calculate the volume of hydrogen gas produced, we need to use the ideal gas law equation, PV = nRT, where P is the pressure in atm, V is the volume in liters, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.
First, we need to obtain the number of moles of hydrogen gas produced by using the balanced equation. According to the equation, 2 moles of HCl produce 1 mole of H2. So, we need to convert the mass of aluminum to moles.
The molar mass of aluminum (Al) is 26.98 g/mol. We can use this information to convert the mass of aluminum to moles:
moles of Al = mass / molar mass
moles of Al = 0.025 g / 26.98 g/mol
Next, we need to determine the number of moles of hydrogen gas produced. Since the balanced equation tells us that 2 moles of HCl produce 1 mole of H2, the number of moles of H2 can be calculated as follows:
moles of H2 = (moles of Al) / 2
Now that we have the number of moles of hydrogen gas, we can proceed to calculate the volume of the gas using the ideal gas law equation.
R, the ideal gas constant, has a value of 0.0821 L·atm/(mol·K).
First, we need to convert the temperature from Celsius to Kelvin:
Temperature (K) = 21 degrees Celsius + 273.15
Now we can calculate the volume of hydrogen gas:
V = (n * R * T) / P
where n is the number of moles calculated earlier, R is the ideal gas constant, T is the temperature in Kelvin, and P is the pressure given in torr. However, to use the ideal gas law, the pressure must be in atm. So we need to convert the pressure from torr to atm.
Pressure (atm) = 755 torr / 760 torr/atm
Now we can substitute the values into the equation and calculate the volume of hydrogen gas:
V = (moles of H2 * R * T) / P
Finally, the volume of H2 will be in liters, so if you want the volume in milliliters, you can multiply the result by 1000.
Remember to use the correct number of significant figures throughout the calculation, and make sure to convert any units as necessary.