How many moles of hydrogen would be required to produce 10 moles of water?

The number to the right of an element's symbol (ex. c-12) identifies the of an isotope.

What is the mass of 2.00 l of an intravenous glucose solution with a density of 1.15 g/ml?

Aroom with dimensions 7.00m×8.00m×2.50m is to be filled with pure oxygen at 22.0∘c and 1.00 atm. the molar mass of oxygen is 32.0 g/mol. how many moles noxygen of oxygen are required to fill the room? what is the mass moxygen of this oxygen?