Stogs GCSE Interleaving Energetics S

In an exothermic reaction...

• energy is taken in and the surroundings get colder.

• energy is taken in and the surroundings get warmer.

• energy is given out and the surroundings get warmer.

• energy is given out and the surroundings get colder.

Calorimetry can be used to measure the energy given off when a substance burns.

• True

• False

Which of these can be used to measure the energy change when a chemical reaction takes place?

• Change in colour.

• Change in mass.

• Change in temperature.

The same reaction is carried out with and without a catalyst. Which line on the graph shows the reaction with a catalyst?

• Line 1

• Line 2

In an endothermic reaction, the products are at...

• a lower energy than the reactants.

• a higher energy than the reactants.

• -386 kJ/mol

• -818 kJ/mol

• +818 kJ/mol

• +386 kJ/mol

Which of these is a unit of energy?

• Joules

• Kelvin

• Kilograms

1.84g if ethanol is burnt in a calorimeter. 40 kJ of energy is transferred to the water. If the formula mass of ethanol is 46, find the energy transferred to the water per mole of ethanol.

• 0.47 kJ/mol

• 19 kJ/mol

• 1000 kJ/mol

• 1.6 kJ/mol

Hydrogen bromide decomposes to form hydrogen and bromine. The table lists some bond energies. Use the bond energies to calculate the overall energy change for the reaction: 2HBr(g) → H₂(g) + Br₂(g)

• -263 kJ/mol

• +103 kJ/mol

• -103 kJ/mol

• +263 kJ/mol

Calculate the energy change for the reaction pictured.

• +122 kJ/mol

• -122 kJ/mol

• -121 kJ/mol

• +121 kJ/mol