Eduqas A-Level Chemistry: C2 (Chemical Change) overview quiz quiz

It decreases, shifting the position toward more gas molecules

It stays exactly the same whatever the pressure

It increases, shifting toward fewer gas molecules

It increases only if a catalyst is also present

$\text{H}_3\text{O}^+$

$\text{H}_2\text{O}$

$\text{OH}^-$

$\text{NO}_3^-$

A strong acid fully dissociates in water, a weak acid only partially dissociates

A strong acid is always far more concentrated than any weak acid in the same solution

A strong acid has more hydrogen atoms per molecule than a weak acid does

A strong acid does not react with reactive metals at all

$2.09\ \text{kJ}$

$20.9\ \text{kJ}$

$209\ \text{kJ}$

$5.23\ \text{kJ}$

$+184\ \text{kJ mol}^{-1}$

$+247\ \text{kJ mol}^{-1}$

$-184\ \text{kJ mol}^{-1}$

$-92\ \text{kJ mol}^{-1}$

Only because collisions between reacting particles become much more frequent at higher temperature

Because the activation energy of the reaction falls as the temperature rises

Because the overall enthalpy change of the reaction becomes more negative

Because a greater proportion of molecules have energy at or above the activation energy

By providing an alternative pathway with a lower activation energy

By lowering the energy of the reactants below that of the products

By increasing the temperature of the reaction mixture itself

By shifting the position of equilibrium toward the products

It starts well above the origin, so some molecules have zero energy

It starts at the origin and the high-energy tail approaches but never reaches zero

It comes down and touches the x-axis again at very high energy

Higher-temperature curves enclose a noticeably larger total area underneath the whole curve

$25.6\%$

$48.9\%$

$51.1\%$

$100\%$

Percentage yield does not depend on the reaction temperature or pressure at all

Percentage yield is always exactly equal to the atom economy

Percentage yield completely ignores the mole ratio of the equation

A reaction can have a high yield but a low atom economy, producing much waste