VCE Chemistry energetics calculations walkthrough quiz

Positive

Negative

Zero

Equal to the activation energy

Mass of the reactant

Mass of the calorimeter water (or solution) absorbing heat

Molar mass of the product

Mass of the limiting reagent

Enthalpy change depends on the route taken

Enthalpy change for a reaction is the same whether it occurs in one step or multiple, depending only on initial and final states

All reactions are exothermic

Enthalpy equals entropy

-1780 kJ

-445 kJ

+445 kJ

+890 kJ

1.67 kJ

6.69 kJ

66.9 kJ

33.4 kJ

Summing energies of bonds in products minus reactants

Summing energies of bonds broken (reactants) minus bonds formed (products)

Adding all bond energies together

Multiplying bond energies by activation energy

Lowers delta H

Lowers activation energy without changing delta H

Increases delta H

Removes the products

Negative

Zero

Always positive

Equal to the molar mass

Water has variable specific heat

The calorimeter itself absorbs heat alongside the contents; the constant captures that

Bomb calorimeters are inaccurate

It increases the temperature reading

I will solve this calorimetry problem.

Calculate Q absorbed using Q = m c delta T, convert to mol of fuel using n = m / M, then use delta H = -Q/n. State the sign convention and significant figures.

Energetics is about heat.

Burning fuel releases energy.