Question

8 gram of H2 combine in the presence of 100 gram of O2 to form water .calculate the amount of oxygen used​

Answer 1

Answer:

As you can see, you need 2 moles of H2 gas and 1 mole of O2 to form 2 moles of H2O.

You are given grams of both hydrogen gas and oxygen. You must find the limiting reagent first. To do this, take the mass of the reactant and convert it into moles.

Now do the mole-to-mole ratio to find out how many moles of #"H"_2"O"# can be produced from each reactant. The reactant to form the least # of moles, is the limiting reagent.

Ex. For #"H"_2(g)#

#"8 grams H"_2 * "1 mole"/(2 "g"/"mole") * ("2 moles H"_2"O")/("2 moles H"_2) = "moles of H"_2"O produced"#

For #"O"_2(g)#

#"8 grams O"_2 * "1 mole"/(32"g"/"mole") * ("2 moles H"_2"O")/"1 mole O"_2 = "moles of H"_2"O produced"#

Once you find the limiting reagent, proceed with finding the mass in grams of #"H"_2"O"# that can be produced and you have your answer