A mixture of Al and Fe weighing 0.2000 g is treated with excess HCl solution. Each metal reacts separately with the acid, resulting in the production of hydrogen gas H2, and a chloride salt. After treatment, a total volume of 200mL of the evolved gas was collected at 20 oC and 850 torr. Calculate for the mass percentage of Al in the sample

Assume the molecular mass of air to be 28.5 g/mol. How many moles of air are above 1 square inch of sea level (all the way to outer space)?

Given the following data from the experiment, calculate the molar volume of hydrogen gas at STP. Be sure to show all of your calculations. Note: You can assume the solution level was the same inside and outside of the tube at the end of the experiment.  Mass of metal used : 0.0862 g Temperature of the gas collected : 24.0 °C Vapor pressure of water at 24 °C : 22.4 torr Volume of gas collected : 89.4 mL Room atmospheric pressure : 757 torr Gas constant : 0.0821 L • atm / K • mol

If 2.50 g of zinc metal is reacted with 400 mL of 0.125 mol/L hydrochloric acid. What volume of hydrogen gas would you expect to produce at 30 °C and 110 kPa?