Consider the balanced chemical equation that follows. you are asked to determine how many moles of water you can form from 4 moles of hydrogen and excess oxygen. 2h2(g)+o2(g)→2h2o(l) which of the following shows calculations for a correct way to solve this problem? view available hint(s) consider the balanced chemical equation that follows. you are asked to determine how many moles of water you can form from 4 moles of hydrogen and excess oxygen. which of the following shows calculations for a correct way to solve this problem? 4 mol h2×2 mol h2o2 mol h2=4 mol h2o 4 mol h2×2 mol h2o1 mol o2=8 mol h2o 2 mol h2×2 mol h22 mol h2o=2 mol h2o

The correct answer is

Explanation:

We are given:

Moles of hydrogen gas = 4 moles

As, oxygen is given in excess. Thus, is considered as an excess reagent and hydrogen is considered as a limiting reagent because it limits the formation of products.

For the given chemical equation:

By Stoichiometry of the reaction:

2 moles of hydrogen produces 2 moles of water molecule.

So, 4 moles of hydrogen will produce = of water.

Hence, the correct answer is

first, consult an activity series chart to determine if al is more reactive than fe. it is, so it will replace the fe. now, one can continue with the problem.

next, make sure you have a correctly balanced equation.

3feo + 2al ==> 3fe + al2o3

now, determine which reactant (feo or al) is in limiting supply.

moles feo present = 125 g x 1 mole/71.8 g = 1.74 moles

moles al present = 25.0 g x 1 mole/26.98 g = 0.927 moles

since from the balanced equation, it take 3 mol feo for every 2 mol al, al will be limiting.

you can determine this simply by dividing moles of each by their coefficient in the balanced equation. for example: 1.74/3 = 0.58 and 0.927/2 = 0.464. al is less, so it is limiting.

finally, using the stoichiometry in the balanced eq. determine mass of fe that can be produced from 0.927 moles of al.

0.927 moles al x 3 moles fe/2 moles al x 55.8 g/mole = 77.6 g

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.