IB Chemistry Topic R3.2.4 Acid-metal Reactions Revision Notes (SL/HL)

IB Chemistry Topic R3.2.4 Acid-metal Reactions Revision Notes (SL/HL) | RevisionDojo

Written by official IB examiners

Acids Reacting with Reactive Metals to Release Hydrogen

When acids react with reactive metals, the metal atoms lose electrons to form positive ions, while hydrogen ions $H^+$ from the acid gain electrons to form hydrogen gas $H_2$.
This process is a redox reaction, a reaction involving both oxidation (loss of electrons) and reduction (gain of electrons).
The general word equation for this reaction is:

$$\text{Metal + Acid → Salt + Hydrogen Gas}$$

Example

When zinc reacts with hydrochloric acid, the products are zinc chloride (a salt) and hydrogen gas: $$
Zn(s) + 2HCl(aq) \rightarrow ZnCl_2(aq) + H_2(g)
$$
Here’s what happens at the atomic level:
- Oxidation: Zinc atoms lose two electrons to form zinc ions ($Zn^{2+}$):
  $$
  Zn(s) \rightarrow Zn^{2+}(aq) + 2e^-
  $$
- Reduction: Hydrogen ions ($H^+$) from the acid gain electrons to form hydrogen gas:
  $$
  2H^+(aq) + 2e^- \rightarrow H_2(g)
  $$
Together, these half-equations illustrate the electron transfer from zinc to hydrogen, which is the hallmark of a redox reaction.

Tip

When writing half-equations, always check that the number of electrons lost in oxidation matches the number gained in reduction.

Example

When zinc reacts with sulfuric acid, a salt (zinc sulfate) and hydrogen gas are produced: $$Zn (s) + H_2SO_4 (aq) \rightarrow ZnSO_4 (aq) + H_2 (g)$$
In this reaction:
- Zinc displaces hydrogen from sulfuric acid due to its higher reactivity.
- Hydrogen gas is released as bubbles.
- Zinc sulfate is formed as an aqueous salt in the solution.
This is a typical example of an acid reacting with a reactive metal to produce hydrogen gas.

Why Do Only Certain Metals React with Acids?

Not all metals react with acids to release hydrogen gas.

Nice try, unfortunately this paywall isn't as easy to bypass as you think. Want to help devleop the site? Join the team at https://revisiondojo.com/join-us. exercitation voluptate cillum ullamco excepteur sint officia do tempor Lorem irure minim Lorem elit id voluptate reprehenderit voluptate laboris in nostrud qui non Lorem nostrud laborum culpa sit occaecat reprehenderit

Definition

Paywall

(on a website) an arrangement whereby access is restricted to users who have paid to subscribe to the site.

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

Duis aute irure dolor in reprehenderit

Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Note

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam quis nostrud exercitation.

Excepteur sint occaecat cupidatat non proident

Nemo enim ipsam voluptatem quia voluptas sit aspernatur aut odit aut fugit, sed quia consequuntur magni dolores eos qui ratione voluptatem sequi nesciunt. Neque porro quisquam est, qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit.

Tip

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

Unlock the rest of this chapter with a free account

Acids Reacting with Reactive Metals to Release Hydrogen

When acids react with reactive metals, the metal atoms lose electrons to form positive ions, while hydrogen ions $H^+$ from the acid gain electrons to form hydrogen gas $H_2$.
This process is a redox reaction, a reaction involving both oxidation (loss of electrons) and reduction (gain of electrons).
The general word equation for this reaction is:

$$\text{Metal + Acid → Salt + Hydrogen Gas}$$

Example

When zinc reacts with hydrochloric acid, the products are zinc chloride (a salt) and hydrogen gas: $$
Zn(s) + 2HCl(aq) \rightarrow ZnCl_2(aq) + H_2(g)
$$
Here’s what happens at the atomic level:
- Oxidation: Zinc atoms lose two electrons to form zinc ions ($Zn^{2+}$):
  $$
  Zn(s) \rightarrow Zn^{2+}(aq) + 2e^-
  $$
- Reduction: Hydrogen ions ($H^+$) from the acid gain electrons to form hydrogen gas:
  $$
  2H^+(aq) + 2e^- \rightarrow H_2(g)
  $$
Together, these half-equations illustrate the electron transfer from zinc to hydrogen, which is the hallmark of a redox reaction.

Tip

When writing half-equations, always check that the number of electrons lost in oxidation matches the number gained in reduction.

Example

When zinc reacts with sulfuric acid, a salt (zinc sulfate) and hydrogen gas are produced: $$Zn (s) + H_2SO_4 (aq) \rightarrow ZnSO_4 (aq) + H_2 (g)$$
In this reaction:
- Zinc displaces hydrogen from sulfuric acid due to its higher reactivity.
- Hydrogen gas is released as bubbles.
- Zinc sulfate is formed as an aqueous salt in the solution.
This is a typical example of an acid reacting with a reactive metal to produce hydrogen gas.

Why Do Only Certain Metals React with Acids?

Not all metals react with acids to release hydrogen gas.

Definition

Paywall

(on a website) an arrangement whereby access is restricted to users who have paid to subscribe to the site.

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Note

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam quis nostrud exercitation.

Excepteur sint occaecat cupidatat non proident

Tip

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

Structure 1. Models of the particulate nature of matter5 subtopics

Structure 2. Models of bonding and structure4 subtopics

Structure 3. Classification of matter2 subtopics

Reactivity 1. What drives chemical reactions?4 subtopics

Reactivity 2. How much, how fast and how far?3 subtopics

Reactivity 3. What are the mechanisms of chemical change?4 subtopics

IB Chemistry R3.2.4 Acid-metal Reactions Notes

Structure 1. Models of the particulate nature of matter5 subtopics

Structure 2. Models of bonding and structure4 subtopics

Structure 3. Classification of matter2 subtopics

Reactivity 1. What drives chemical reactions?4 subtopics

Reactivity 2. How much, how fast and how far?3 subtopics

Reactivity 3. What are the mechanisms of chemical change?4 subtopics

Acids Reacting with Reactive Metals to Release Hydrogen

Why Do Only Certain Metals React with Acids?

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account

Acids Reacting with Reactive Metals to Release Hydrogen

Why Do Only Certain Metals React with Acids?

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account