metals and acids

Question 1

What do metals produce when they react with acids?

Answer 1

A salt and hydrogen gas

Example: magnesium + hydrochloric acid → magnesium chloride + hydrogen.

Question 2

Write the chemical equation for magnesium reacting with hydrochloric acid using state symbols.

Answer 2

Mg(s) + 2HCl(aq) → MgCl₂(aq) + H₂(g)

This represents the reaction of magnesium with hydrochloric acid.

Question 3

What do some metals form when they react with water or steam?

Answer 3

Metal hydroxide (or oxide) and hydrogen gas

Example: potassium reacts with cold water.

Question 4

Write the chemical equation for potassium reacting with water.

Answer 4

2K(s) + 2H₂O(l) → 2KOH(aq) + H₂(g)

This shows potassium’s reaction with cold water.

Question 5

What is the purpose of the pop test?

Answer 5

To test for hydrogen gas

A lit splint makes a pop sound when hydrogen is present.

Question 6

What do metals form when they react with oxygen?

Answer 6

Metal oxides

Example: 2Mg(s) + O₂(g) → 2MgO(s).

Question 7

What is the reactivity series?

Answer 7

A ranking of metals from most reactive to least reactive

Examples: potassium and calcium are most reactive; copper and gold are least reactive.

Question 8

What can be predicted from the reactivity series?

Answer 8

How a metal will behave in reactions

Especially in displacement reactions.

Question 9

What happens in a displacement reaction?

Answer 9

A more reactive metal replaces a less reactive one in a compound

Example: zinc + copper sulfate → zinc sulfate + copper.

Question 10

Write the chemical equation for zinc displacing copper in copper sulfate.

Answer 10

Zn(s) + CuSO₄(aq) → ZnSO₄(aq) + Cu(s)

This illustrates the displacement reaction.

Question 11

Understanding metal reactivity helps us predict outcomes in chemistry and perform experiments safely. True or False?

Answer 11

True

Knowledge of reactions and the reactivity series is essential for safe experimentation.