To determine which method will produce more hydrogen molecules, convert equal masses of each reactant into molecules of hydrogen gas. The conversion requires us to convert the initial compound to moles, multiply by the molar ratio from the reaction to find moles of hydrogen, and multiply by Avogadro's number to convert to molecules.

Dividing these solutions, we see that the methane method produces roughly eight times the amount of hydrogen molecules.

In order to identify an excess reactant, we use stoichiometry to convert atoms of iron to mass of steam.

We have of steam available, but only require  to fully react the given iron. Iron is thus the limiting reagent, since it will be fully consumed first.

There will be  of excess steam.

First, write a balanced equation for the reaction.

Next, convert 10g BaCO₃ to milliliters of NaOH.

We will be looking for a solution that results in one mole of potassium chloride per ten liters of water.

We will need to find the molecular weight of potassium chloride.

In order to get the desired concentration, we will need to add one-tenth of this amount to one liter of water.

Our ratio, then is:

The only answer to follow this ratio is of potassium chloride in .

This is a stoichiometry question requiring us to convert between grams, moles, reactants, and products.

Use the periodic table to find the molar masses of the two compounds in question.

We can use the reaction formula to find the ratio of aluminum chloride to silver chloride. In this case, the ratio is 1:3.

Now we can set up a calculation to convert grams of aluminum chloride to grams of silver chloride, making sure that all units cancel appropriately.

The question asks us to consider water scarcity. Assuming our goal is to utilize minimal water to produce maximal hydrogen, the natural gas method is most efficient as is produces more hydrogen per mole of water consumed.

One mole of water produces three moles of hydrogen.

Four moles of water produce four moles of hydrogen.

Find the volume of hydrochloric acid (HCl) needed to react completely with 5.6g of manganese (Mn).

Since we only need 85mL of acid to react with 5.6g manganese, we have an excess of 565mL hydrochloric acid, and manganese is the limiting reagent.  

Convert 5.6g of manganese (limiting reagent) to volume of hydrogen gas.

The reaction given is the complete oxidation of glucose. Reactants are glucose and oxygen (from inhalation) and products are carbon dioxide and water, which are released through exhalation and excretion.

The complete balanced reaction is:

When balancing reactions, it is generally easiest to leave oxygen and hydrogen alone until the end. First, balance the carbon. Next, balance the hydrogen since it is only found in one reactant molecule and one product molecule. Finally, balance the oxygen.

The first step to solve will be to balance the chemical reaction:

We see that we see that for every one mole of glucose used, six moles of carbon dioxide will be made. Similarly, for every six moles of oxygen used, six moles of carbon dioxide will be formed. For the reaction to carry out to completion, however, there must exist six moles of oxygen for every one mole of glucose. In the problem's circumstances, one of these compounds becomes the limiting reactant, in this case it is oxygen.

We only have three moles of oxygen, but we would need six to react all the given glucose, making oxygen the limiting reagent. We need to find the carbon dioxide produced from the limited amount of oxygen present. Use the molar ratio between oxygen and carbon dioxide and the molar mass of carbon dioxide to solve.