If 7.8 grams of methane gas is reacted with excess oxygen gas yielding 16.0 grams of water, what was the percent yield of the reaction?

Does anyone know a lot about how to: - calculate mass of magnesium metal - calculate the actual yield of magnesium oxide - calculate the theoretical yield of mgo - calculate the percent yield of mgo - determine the percent yield of mgo - determine the average percent yield of mgo i had to do an online lab and its asking these questions but i have no idea where to start or how to be able to find these things. i can post the chart of the data from the lab or if you can tell me exactly how i can find each.

If 1.63 times 10 negative 4 of helium dissolves in 100.0g of water, what is the concentration in parts per million

(1.6 × 10-19)(5.0 × 106) = c × 10d identify the missing numbers below to show the result of multiplying the numbers.