The combustion of propane (C3H8)produces CO2 and H20: C3H8(g)+5O2(g) 3CO2(g)+4H2O(g) Calculate the mass, in grams, of H2O that will be produced if 2.5 mol of O2 is consumed.

You do mol×molar mass which is 2.5×18 and the answer is 45g. Hope this answered your question correctly:)

To calculate the mass of H2O produced, we need to determine the amount of propane consumed and use the stoichiometry of the reaction to determine the amount of water produced.

First, we need to find the number of moles of propane (C3H8) consumed. The stoichiometry of the reaction tells us that for every 5 moles of oxygen (O2) consumed, 1 mole of propane is consumed. Therefore, we can set up a proportion:

(5 moles of O2) / (1 mole of C3H8) = (2.5 moles of O2) / (x moles of C3H8)

Using cross-multiplication and solving for x, we find that x = (2.5 moles of O2) / (5 moles of O2) = 0.5 moles of C3H8.

Next, we need to determine the number of moles of water (H2O) produced. From the balanced equation, we see that for every 1 mole of propane consumed, 4 moles of water are produced. Therefore:

(1 mole of C3H8) / (4 moles of H2O) = (0.5 moles of C3H8) / (y moles of H2O)

Solving for y, we find that y = (0.5 moles of C3H8) * (4 moles of H2O) / (1 mole of C3H8) = 2 moles of H2O.

Finally, we can calculate the mass of water produced using the molar mass of water. The molar mass of H2O is approximately 18 g/mol. Therefore:

Mass of H2O = (2 moles of H2O) * (18 g/mol) = 36 grams.

So, the mass of H2O produced when 2.5 mol of O2 is consumed is 36 grams.