select the correct answer.\ngiven:\n2h₂o₂ → 2h₂o + o₂\nstructure of h₂o₂:\nh - o - o - h\n|bond|bond energy…

select the correct answer.\ngiven:\n2h₂o₂ → 2h₂o + o₂\nstructure of h₂o₂:\nh - o - o - h\n|bond|bond energy (kj/mol)|\n|o - h|459|\n|o = o|494|\n|o - o|142|\nbased on the given bond energies, what is the enthalpy change for the chemical reaction?\na. -352 kj\nb. -210 kj\nc. -176 kj\nd. -105 kj
Answer
Explanation:
Step1: Calculate bonds broken
In 2 moles of $H_2O_2$, there are 4 O - H bonds and 2 O - O bonds. Energy for bonds broken: $4\times459+2\times142=1836 + 284=2120$ kJ/mol
Step2: Calculate bonds formed
In 2 moles of $H_2O$, there are 4 O - H bonds, and in 1 mole of $O_2$ there is 1 O = O bond. Energy for bonds formed: $4\times459+494=1836+494 = 2330$ kJ/mol
Step3: Calculate enthalpy change
$\Delta H=$ Energy of bonds broken - Energy of bonds formed $\Delta H=2120 - 2330=- 210$ kJ/mol
Answer:
B. -210 kJ