5.0 g of aluminum reacts with 50.0 mL of 6.0 M hydrochloric acid to produce
hydrogen gas. What is the volume of gas collected if the gas was collected at STP?
3. A 0.418 g sample of gas has a volume of 115 mL at 66.3 °C and 743 mmHg. What is
the molar mass of this gas?
2 answers
stop wasting everyone's time reposting the same thing over and over!
This is a limiting reagnt (LR) problem. You know that when amounts are given for BOTH reactants.
2Al + 6HCl ==>2 AlCl3 + 3H2
mols Al = grams/atomic mass
mols HCl = M x L = ?
Convert mols Al to mols H2 using the coefficients in the balanced equation. You can see that 2 mols Al = 3 mols H2.
Convert mols HCl to mols H2 .
In LR problems, the SMALLER number wins and that will be the mols H2 produced.
Volume is calculated using PV = nRT OR remembering that 1 mole of any gas occupies 22.4 L at STP.
For #3. use PV = nRT
Post your work if you get stuck.
2Al + 6HCl ==>2 AlCl3 + 3H2
mols Al = grams/atomic mass
mols HCl = M x L = ?
Convert mols Al to mols H2 using the coefficients in the balanced equation. You can see that 2 mols Al = 3 mols H2.
Convert mols HCl to mols H2 .
In LR problems, the SMALLER number wins and that will be the mols H2 produced.
Volume is calculated using PV = nRT OR remembering that 1 mole of any gas occupies 22.4 L at STP.
For #3. use PV = nRT
Post your work if you get stuck.
1 answer