Question

Water, H2O, is made via its formation reaction. How many moles of water form when (7.69x10^0) moles of oxygen gas react? (Answer in mol to 3 s.d. in proper scientific notation)

yet again, i have no idea what im doing

Answer 1

The given amount of oxygen gas will produce `1.54xx10^1` mol water.

Explanation:

Start with a balanced equation. It will be used to determine mol ratios between the product and the reactant.

`"2H"_2 + "O"_2` `rarr` `"2H"_2"O"`

Multiply the given mol oxygen gas by the mol ratio `(2"mol H"_2"O")/(1"mol O"_2")` from the balanced equation.

`7.69xx10^0color(red)cancel(color(black)("mol O"_2))xx=(2"mol H"_2"O")/(1color(red)cancel(color(black)("mol O"_2)))=1.54xx10^1color(white)(.)"mol H"_2"O"`