Methane burns in oxygen to produce carbon dioxide and water according to the equation above.
If 1.20 X 10²³ number of methane molecules completely burn in excess oxygen calculate the number of water molecules formed.

Step 1 Calculate the number of mole of methane present.

Step 2 Calculate the ratio from the prefixes in the balanced equation above

Step 3 Calculate the number of mole of water produced.

Step 4 Calculate the number of water molecules produced.