I'm a bit stuck, please helppp

Problem page gaseous ethane reacts with gaseous oxygen gas to produce gaseous carbon dioxide and gaseous water . if of water is produced from the reaction of of ethane and of oxygen gas, calculate the percent yield of water. be sure your answer has the correct number of significant digits in it.

How are elements arranged in a periodic table

Match the name of the following compound:   mgso4  · h2omagnesium sulfate monohydratemagnesium (ii) sulfate monohydratemagnesium (ii) sulfate hydratemagnesium sulfate hydrate