Copper(II) oxide catalyses the decomposition of hydrogen peroxide. $0.5 \mathrm{g}$ of the oxide was added to a flask containing $100 {\mathrm{cm}}^3$ of hydrogen peroxide solution. A gas was releases. It was collected, and its volume noted every $10$ seconds. This table shows the results:

Time / $\mathrm{s}$	$0$	$10$	$20$	$30$	$40$	$50$	$60$	$70$	$80$	$90$
Volume / ${\mathrm{cm}}^3$	$0$	$18$	$30$	$40$	$48$	$53$	$57$	$58$	$58$	$58$

Plot a graph of the volume of gas (vertical axis) against time (horizontal axis).

Copper(II) oxide catalyses the decomposition of hydrogen peroxide. $0.5 \mathrm{g}$ of the oxide was added to a flask containing $100 {\mathrm{cm}}^3$ of hydrogen peroxide solution. A gas was releases. It was collected, and its volume noted every $10$ seconds. This table shows the results:

Describe how rate changes during the reaction.

Copper(II) oxide catalyses the decomposition of hydrogen peroxide. $0.5 \mathrm{g}$ of the oxide was added to a flask containing $100 {\mathrm{cm}}^3$ of hydrogen peroxide solution. A gas was releases. It was collected, and its volume noted every $10$ seconds. This table shows the results:

What happens to the concentration of hydrogen peroxide as the reaction proceeds?

Copper(II) oxide catalyses the decomposition of hydrogen peroxide. $0.5 \mathrm{g}$ of the oxide was added to a flask containing $100 {\mathrm{cm}}^3$ of hydrogen peroxide solution. A gas was releases. It was collected, and its volume noted every $10$ seconds. This table shows the results:

What chemicals are present in the flask after $90$ seconds?

Copper(II) oxide catalyses the decomposition of hydrogen peroxide. $0.5 \mathrm{g}$ of the oxide was added to a flask containing $100 {\mathrm{cm}}^3$ of hydrogen peroxide solution. A gas was releases. It was collected, and its volume noted every $10$ seconds. This table shows the results:

What mass of copper(II) oxide would be left in the flask at the end of the reaction?

Copper(II) oxide catalyses the decomposition of hydrogen peroxide. $0.5 \mathrm{g}$ of the oxide was added to a flask containing $100 {\mathrm{cm}}^3$ of hydrogen peroxide solution. A gas was releases. It was collected, and its volume noted every $10$ seconds. This table shows the results:

Sketch on your graph the curve that might be obtained for $1.0 \mathrm{g}$ of copper(II) oxide.

Copper(II) oxide catalyses the decomposition of hydrogen peroxide. $0.5 \mathrm{g}$ of the oxide was added to a flask containing $100 {\mathrm{cm}}^3$ of hydrogen peroxide solution. A gas was releases. It was collected, and its volume noted every $10$ seconds. This table shows the results:

Name one other substance that catalyses this decomposition.

Marble chips (lumps of calcium carbonate) react with hydrochloric acid as follows:

${\mathrm{CaCO}}_3\left(\mathrm{s}\right)+2\mathrm{HCl}\left(\mathrm{aq}\right)\to {\mathrm{CaCl}}_2\left(\mathrm{aq}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$

What gas is released during this reaction?

Marble chips (lumps of calcium carbonate) react with hydrochloric acid as follows:

${\mathrm{CaCO}}_3\left(\mathrm{s}\right)+2\mathrm{HCl} \left(\mathrm{aq}\right)\to {\mathrm{CaCl}}_2 \left(\mathrm{aq}\right)+{\mathrm{CO}}_2 \left(\mathrm{g}\right)+{\mathrm{H}}_2\mathrm{O} \left(\mathrm{l}\right)$

Describe a laboratory method that could be used to investigate the rate of the reaction.