Reactivity series and displacement reactions
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レッスンノート
Reactivity of Metals
- Metals differ in how strongly they react with water or acid; this is due to differences in reactivity.
- More reactive metals produce more bubbles of hydrogen when placed in acid.
- The reactivity series lists metals in order of reactivity, from most to least reactive.
- Carbon and hydrogen are included in the series even though they are not metals, to help predict reactions.
Testing Reactivity
- Place metals in hydrochloric acid; the rate of bubble production shows reactivity.
- Magnesium reacts vigorously, copper shows no reaction.
- Reactions with water also indicate reactivity; more reactive metals react more vigorously.
Displacement Reactions
- A displacement reaction occurs when a more reactive element replaces a less reactive element in a compound.
- Example: iron displaces copper from copper sulfate: iron + copper sulfate → iron sulfate + copper.
- No reaction occurs if the displacing element is less reactive (e.g., gold with copper sulfate).
- Another example: aluminium displaces iron from iron oxide: aluminium + iron oxide → aluminium oxide + iron.
Signs of a Chemical Reaction
- Gas release (bubbles) indicates a reaction.
- Colour change is another sign; e.g., blue copper sulfate turns green when iron displaces copper.
- In the magnesium–copper sulfate reaction, the blue colour fades to colourless.
Using the Reactivity Series
- A metal can only displace another metal if it is higher in the reactivity series.
- For example, magnesium displaces lead from lead nitrate because magnesium is more reactive.
- Calcium cannot displace sodium from sodium carbonate because calcium is less reactive than sodium.
Example Word Equations
- Aluminium + iron oxide → aluminium oxide + iron
- Magnesium + copper chloride → magnesium chloride + copper
- Zinc + iron sulfate → zinc sulfate + iron
Particle arrangement in solids, liquids, and gases. Reactivity relates to how easily atoms can lose electrons.
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練習問題
無料プレビュー — 62問中8問。すべて見るには登録を。
1.Which of the following is the correct order of reactivity, from most reactive to least reactive?
Easy- AMagnesium > Copper > Iron
- BCopper > Iron > Magnesium
- CMagnesium > Iron > Copper
- DIron > Magnesium > Copper
2.What is the sign of a chemical reaction when a metal is placed in acid?
Easy- AA colour change
- BBubbles of gas
- CA solid precipitate
- DA temperature decrease
3.In the reaction: iron + copper sulfate → iron sulfate + copper, which metal is displaced?
Medium- AIron
- BCopper
- CSulfate
- DBoth iron and copper
4.Which of the following is NOT a sign of a chemical reaction?
Easy- AA colour change
- BA gas being released
- CA change of state
- DThe mixture becoming colder
5.Why is carbon often included in the reactivity series even though it is not a metal?
Medium- ABecause it reacts with metals
- BBecause it helps predict displacement reactions
- CBecause it is the most reactive element
- DBecause it is a metal
6.What colour is copper sulfate solution?
Easy- AGreen
- BBlue
- CColourless
- DRed
7.Which statement about the reaction between gold and copper sulfate is correct?
Medium- AGold displaces copper because gold is more reactive
- BCopper displaces gold because copper is more reactive
- CNo reaction occurs because gold is less reactive than copper
- DNo reaction occurs because both are unreactive
8.In a displacement reaction, a more reactive element replaces a less reactive element in a compound. True or false?
Easy- ATrue
- BFalse
- COnly if both are metals
- DOnly if the compound is an oxide