Look at the diagram of the reactivity series. It shows some metals in order of reactivity. Name a metal in the diagram that will not react with dilute acid.

Metals below hydrogen in the reactivity series are less reactive and hence, don't have the tendency to displace hydrogen from dilute acids. So the metals copper, silver, gold and platinum will not displace hydrogen from dilute acid.

Look at the diagram of the reactivity series. It shows some metals in order of reactivity. Name a metal that will react with cold water.

Metals placed on the top of the reactivity series are extremely reactive that they can react even with cold water and displaces hydrogen gas. These metals are potassium, sodium and calcium.

Look at the diagram of the reactivity series. It shows some metals in order of reactivity. Name two metals that react slowly with hydrochloric acid.

The metals which are placed just above the hydrogen in the reactivity series are the moderate reactive metals and hence reacts with hydrochloric acid very slowly. These metals are lead and tin.

Look at the diagram of the reactivity series. It shows some metals in order of reactivity. Complete this word equation: calcium + hydrochloric acid → _____ + _____

Metals react with acids to make corresponding salts and liberate hydrogen gas. Since, calcium is above hydrogen in the reactivity series it is capable to displace hydrogen from the acid. The complete word reaction is as follows: calcium + hydrochloric acid → calcium chloride + hydrogen

EASY

Lower Secondary Stage 9

IMPORTANT

Earn 100

Aiko investigates the reaction between magnesium and hydrochloric acid.

She adds $1 Cm$ length of magnesium to $25 {cm}^{3}$ of the acid.

She measures the time it takes for all the magnesium to react.

She then repeats the experiment at different temperatures.

The table shows her results:

Temperature $(° C)$ Time for magnesium (s)

$20$ $181$

$30$ $112$

$40$ $49$

$50$ $43$

$60$ $26$

Which temperature shows the fastest reaction?

Important Questions on Reactivity and Rates of Reaction

MEDIUM

Lower Secondary Stage 9

IMPORTANT

Cambridge Lower Secondary Science Stage 9: Workbook>Chapter 7 - Reactivity and Rates of Reaction>Test-style questions>Q 1

Aiko investigates the reaction between magnesium and hydrochloric acid.

She adds $1 Cm$ length of magnesium to $25 {cm}^{3}$ of the acid.

She measures the time it takes for all the magnesium to react.

She then repeats the experiment at different temperatures.

The table shows her results:

Temperature $(° C)$	Time for magnesium (s)
$20$	$181$
$30$	$112$
$40$	$49$
$50$	$43$
$60$	$26$

Which data point does not fit the pattern? What should Aiko do with this data point?

MEDIUM

Lower Secondary Stage 9

IMPORTANT

Cambridge Lower Secondary Science Stage 9: Workbook>Chapter 7 - Reactivity and Rates of Reaction>Test-style questions>Q 2

Mary and Mia are making lemonade. They add some sugar to make it sweeter. Mary adds three sugar cubes to her lemonade. Mia adds the same mass of sugar granules to her lemonade.

Whose sugar will dissolve first? Give a reason for your answer.

MEDIUM

Lower Secondary Stage 9

IMPORTANT

Cambridge Lower Secondary Science Stage 9: Workbook>Chapter 7 - Reactivity and Rates of Reaction>Test-style questions>Q 2

Mary and Mia are making lemonade. They add some sugar to make it sweeter. Mary adds three sugar cubes to her lemonade. Mia adds the same mass of sugar granules to her lemonade.

What could Mia do to speed up the rate at which her sugar dissolves?

MEDIUM

Lower Secondary Stage 9

IMPORTANT

Cambridge Lower Secondary Science Stage 9: Workbook>Chapter 7 - Reactivity and Rates of Reaction>Test-style questions>Q 2

Mary and Mia are making lemonade. They add some sugar to make it sweeter. Mary adds three sugar cubes to her lemonade. Mia adds the same mass of sugar granules to her lemonade.

Use your ideas about particles to explain your answer to what could Mia do to speed up the rate at which her sugar dissolves?

MEDIUM

Lower Secondary Stage 9

IMPORTANT

Cambridge Lower Secondary Science Stage 9: Workbook>Chapter 7 - Reactivity and Rates of Reaction>Test-style questions>Q 3

Look at the diagram of the reactivity series. It shows some metals in order of reactivity.

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