Unit 2: Energy, Rate and Chemistry of Carbon Compounds overview quiz - WJEC A-Level Chemistry quiz

An exothermic reaction that releases heat

An endothermic reaction that absorbs heat

A reaction at equilibrium

A reaction with no energy change

$q = m / c$

$q = mc\Delta T$

$q = c\Delta T / m$

$q = mcT$

always exothermic

equal to the activation energy

independent of the route taken

zero at equilibrium

Every single collision between the reacting molecules becomes successful

The activation energy of the reaction falls as the temperature increases

The molecules stop colliding altogether and instead react on their own

A much greater proportion of molecules exceed the activation energy

By providing an alternative pathway with a lower activation energy

By raising the activation energy needed for the reaction to proceed

By increasing the overall enthalpy change of the reaction taking place

By being steadily used up in the reaction as it converts into products

It guarantees that the reaction will always give a high percentage yield

More reactant mass becomes the desired product, reducing waste

It speeds up the rate of the reaction so the product forms more quickly

It lowers the activation energy of the reaction taking place in the plant

Free-radical substitution

Nucleophilic substitution

Electrophilic addition

Elimination

It stays orange with no change occurring

It turns from orange to a deep blue colour

It turns from orange to a bright green colour

It turns from orange to colourless

Hot ethanolic (alcoholic) sodium hydroxide

Warm dilute aqueous sodium hydroxide solution

Cold water at ordinary room temperature

Cold dilute sulfuric acid solution alone

A ketone and then nothing further

A carboxylic acid

An aldehyde and no further product

An ester of the original alcohol

They have no oxygen atom anywhere in the alcohol molecule at all

They are far too volatile and evaporate before they can be oxidised

There is no hydrogen on the carbon bearing the OH group

They are already fully oxidised as far as they can possibly go