When gas is burned:

CH4 + 2O2 = CO2 + 2H2O,
how many moles of water are produced when 6.2 mol of methane are burned?

To determine the number of moles of water produced when 6.2 mol of methane (CH4) is burned, we can use the balanced chemical equation given:

CH4 + 2O2 -> CO2 + 2H2O

From the equation, we can see that 1 mole of methane produces 2 moles of water.
So, to find the number of moles of water produced when 6.2 mol of methane is burned, we can use the following ratio:

2 moles H2O per 1 mole CH4

Therefore, we calculate:

Number of moles of water = 2 moles H2O/1 mole CH4 * 6.2 moles CH4

Number of moles of water = 12.4 moles of H2O

Therefore, 6.2 mol of methane will produce 12.4 moles of water.