chemistry

posted by .

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.

  • chemistry -

    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.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Chemistry

    Two more questions. To prepare a sample of hydrogen gas, as studen reacts zinc w/ hydrochloric acid. The hydrogen is collected over water at 22c and the total pressue is 750 mm hg. What is the partial pressue of H2?
  2. Chemistry

    A 0.0677g sample of magnesium metal reacted with excess hydrochloric acid to produce 69.9 ml of hydrogen gas. The gas was collected over water at 21.0 degrees Celsius. The levels of water inside and outside the gas collecting tube …
  3. chemistry

    A 0.0677 g sample of magnesium metal reacted with excess hydrochloric acid solution to produce 69.9 mL of hydrogen gas. The gas was collected over water at 21.0° C. The levels of water inside and outside the gas collecting tube are …
  4. chemistry

    Hydrogen gas can produced by the reaction between metallic aluminum and aqueous hydrochloric acid 2Al+6HCl----2AlCl3+3H2 Hydrogen gas produced by this reaction is typically collected via water displacement, during which time the hydrogen …
  5. chemistry

    Hydrogen gas produced by this reaction is typically collected via water displacement, during which time the hydrogen gas becomes saturated with water vapor. If 238.4 mL of gas with a total pressure 1.27 atm was collected via water …
  6. Chemistry

    Al and Fe react with HCl to produce a chloride salt and hydrogen gas. A .1924g sample of a mixture of Al and Fe is treated with excess HCl solution. A volume of 159mL h2 gas is collected over water at 19C and 841 torr. What is the …
  7. Chemistry

    Calculate the percent purity of a sample of zinc metal if 325 mL of hydrogen gas is collected by water displacement at a temperature of 22.0 C and an atmospheric pressure of 745.0 mm Hg when 1.12 g of the sample is reacted with excess …
  8. science

    When the metal sample reacts with acid, the gas evolved will be collected over water; the gas is said to be "wet". What is the composition of the wet gas?
  9. 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) …
  10. Chemistry

    In need of help setting up each of these problems. Under the conditions in a laboratory experiment, 0.0513 grams of aluminum (At. Wt.=27.0) was reacted with excess hydrochloric acid to produce hydrogen gas according to the following …

More Similar Questions