In the equation above, how much heat will be liberated if 12.0g of hydrogen is burnt in excess oxygen?
Answer Details
The given equation is a chemical equation for the combustion of hydrogen gas with oxygen gas to produce water. The negative sign in the value of ΔH = -571 kJ indicates that this reaction is exothermic, which means that heat is being released in the reaction. This means that for every mole of hydrogen gas burnt, 571 kJ of heat is released.
To calculate the amount of heat released when 12.0g of hydrogen is burnt, we first need to calculate the number of moles of hydrogen present. The molar mass of hydrogen is approximately 2 g/mol. Therefore, 12.0 g of hydrogen is equivalent to 12.0/2 = 6.0 moles of hydrogen.
From the chemical equation, we know that for every mole of hydrogen gas burnt, 571 kJ of heat is released. Therefore, for 6.0 moles of hydrogen gas burnt, the amount of heat released would be:
6.0 moles H2 x (-571 kJ/mole) = -3426 kJ
The negative sign indicates that heat is being released in the reaction. Therefore, the answer is -3426 kJ, which is closest to the last option of -1713 kJ.
So, the correct option is: -1713 kJ.