Hydrogen gas is a very useful reagent with many uses in the petroleum, food, and chemical industries. Most hydrogen exists in covalently bonded molecules, and atmospheric air contains less than 1 ppm of diatomic hydrogen. Therefore, hydrogen gas is produced on a large scale for these uses, where steam reforming with methane and electrolysis of water are two of the primary methods. The more economic reaction of steam reforming is the reverse of the reaction depicted in Carbon Monoxide and Hydrogen - Sample 1 in the simulation.
Hydrogen has also been considered as an alternative fuel for vehicles designed to combust hydrogen and oxygen, which produces water as a product. However, concerns were raised because methane is typically used on a large scale to produce hydrogen gas. Assume that a gallon of gasoline contains 2400 g of carbon. If a gasoline engine achieves 30 miles per gallon, each mile consumes 80 g of carbon (since about 107 g of methane contains 80 g of carbon). Alternatively, a hydrogen engine can achieve 80 miles per kilogram of hydrogen gas.
What is the mass of methane (CH4) needed to produce enough hydrogen gas (H2) to drive one mile using the theoretical hydrogen engine?
Express the mass in grams to two significant digits.
Carbon monoxide (CO) can react with hydrogen gas (H2) to form methanol (CH3OH) as shown in the Carbon Monoxide and Hydrogen - Sample 2 reaction in the simulation. The same reactants can also form methane (CH4) and water (H2O) as shown in the Carbon Monoxide and Hydrogen - Sample 1 reaction in the simulation. The latter reaction (Sample 1) is actually more commonly employed in reverse as a method for producing hydrogen gas, a process known as steam reforming, but it requires a lot of heat.
For the following exercises, you can track and confirm the amounts of reactants and products (in both moles and mass) using the Run Experiment tool under the Experiment tab in the simulation. Note that the simulation checks your values to a different number of significant digits than this tutorial. We will explore these two reactions of carbon monoxide and hydrogen.
Frequently Asked Questions
What scientific concept do you need to know in order to solve this problem?
Our tutors have indicated that to solve this problem you will need to apply the Stoichiometry concept. You can view video lessons to learn Stoichiometry. Or if you need more Stoichiometry practice, you can also practice Stoichiometry practice problems.