Final answer:
The amount of heat released when 52.9 g of diborane is burned is calculated by determining the number of moles of diborane and then multiplying by the enthalpy change of the reaction.
Step-by-step explanation:
To calculate the amount of heat released when 52.9 g of diborane is burned, we can use the provided stoichiometry of the reaction and the enthalpy change, ΔH. The balanced chemical equation is:
B2H6(g) + 3 O2(g) → B2O3(s) + 3 H2O(g), ΔH = -2035 kJ/mol
First, calculate the molar mass of diborane (B2H6) which is 27.67 g/mol. Then, determine the number of moles of diborane in 52.9 g:
Moles of B2H6 = 52.9 g / 27.67 g/mol
This calculation gives us the moles of B2H6 that will react. Afterwards, we can use the enthalpy change to find the heat released:
Heat released = Moles of B2H6 × ΔH
Since the reaction releases -2035 kJ per mole of B2H6, we just multiply the number of moles by -2035 kJ/mol for the heat released. Remember that the negative sign for enthalpy change indicates that the reaction is exothermic, so the calculated number (without the sign) represents the amount of heat released.