chemistry

A 0.052g sample of aluminium reacts with excess 6M HCL. A 48.3mL volume of hydrogen gas was collected over water at 22C and the pressure of the hydrogen gas was 751mmHg.calculate the aluminum percent purity in the sample.
What volume of hydrogen gas at STP is produced from the reaction of 0.044g of 98.0% pure aluminium with excess 6M HCl.

  1. 0
  2. 0
  3. 8
asked by jeffrisa
  1. A.
    2Al + 6HCl ==> 2AlCl3 + 3H2
    Look up vapor pressure H2O @ 22 C = and I've estimated 22 mm
    Use PV = nRT to solve for mols H2 evolved.
    For P you have
    Ptotal = pH2 + pH2O
    751 mm = pH2 + 22
    Therefore, estimated pH2 = 751-22 = approx 729. Use that for P in the PV = nRT formula.
    Remember T must be in kelvin; solve for n.
    Using the coefficients in the balanced equation, convert mols H2 to mols Al.
    Then g Al = mols Al x atomic mass Al.

    %Al = (grams Al from calcn/0.052)*100 = ?%

    B.
    This is just the reverse process from part A above. This should get you started.
    mass Al = 0.044 x 0.98 = ?
    Convert to mols H2 from the equation.
    Convert mols H2 to volume remembering that 1 mol at STP occupies 22.4 L.

    1. 0
    2. 0
    posted by DrBob222

Respond to this Question

First Name

Your Response

Similar Questions

  1. Chemistry 171 Lab

    Suppose we collect hydrogen gas, H2(g), over water at 21◦C in a vessel with total pressure of 743 Torr. If the hydrogen gas is produced by the reaction of aluminum with hydrochloric acid: 2Al(s) + 6HCl(aq) → 2AlCl3(aq) +
  2. Chem

    Ca(s) + 2H+(aq) → Ca2+(aq) + H2(g) An experiment is performed to determine the volume of hydrogen gas produced when calcium reacts with excess HCl(aq) as represented by the net ionic equation above. A 0.0720 g sample of pure
  3. chemistry

    A co-op student designed an experiment to collect hydrogen gas by reacting iron with a hydrochloric acid (HCl) solution. The student’s co-op supervisor suggested that aluminum can also be included to generate hydrogen gas: Fe +
  4. SCIENCE/CHEM

    the purity of zinc is to be determined by measuring the amount of hydrogen formed when a weighed sample of zinc reacts with an excess of HCL acid.the sample weighs 0.198 grams. what amount of hydrogen gas at STP will be obtained
  5. chemistry

    1- A compound is 87.5% nitrogen and 12.5% hydrogen. The molecular weight of the compound is 32 g/mol. Describe the molecule referencing shape, and inter-molecular forces. 2- Gaseous butadiene, C4H6 , reacts with hydrogen gas in
  6. Chemistry 101

    Iron reacts with hydrochloric acid to produce iron (2) chloride and hydrogen gas.Fe (s)+ 2 HCL (aq) -FeCl2 (aq) + H2 (g).The hydrogen gas from the reaction 2.2g of iron with excess acid is collected in a 10L flask at 25 degrees
  7. chemisty

    If 26.5 mL of 0.222 M HCl reacts with excess Mg, how many mL of hydrogen gas are produced at STP?
  8. Chemistry

    When potassium cyanide (KCN) reacts with acids, a deadly poisonous gas, hydrogen cyaninde (HCN) is given off. Here is the equation: KCN(aq) + HCl(aq) ----> KCl(aq)+ HCN(g) If a sample of 0.140 g of KCN is treated with an excess of
  9. chemistry

    If 35.0 mL of 0.210 M HCl reacts with excess Mg, how many mL of hydrogen gas are produced at STP? Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
  10. chemistry

    Potassium cyanide (KCN) reacts with acids to produce the poisonous hydrogen cyanide gas, HCN, according to the reaction below: KCN(aq) + HCl(aq) = HCN(g) + KCl(aq) If a sample of 0.653 g of KCN is placed in an excess of HCl, how

More Similar Questions