When 4.0 mol h2 reacts with excess o2, 3.0 mol h2o are actually produced, what is the percent yield of the reaction? 2h2 + o2 > 2h2o a. 25% b.50% c.75% d.100%

2H2 + O2 --->2H2O

from equation 2 mol 2 mol

given 4 mol 3 mol

How much

we could get

using 4 mol of H2. 4 mol x mol

2 mol H2 gives 2 mol H2O, 4 mol H2 could give 4 mol H2O.

So, 4 mol H2O is theoretical yield.

% yield = (actual yield/theoretical yield)*100% = (3 mol/4 mol)*100% = 75 %

Answer is C. 75%.

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

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