Chemistry: Acids and Alkalis

What type of ions do acids produce in water?

Sulfuric acid produces chlorides when it neutralizes an alkali.

What is the result of the neutralization reaction of an acid with an alkali?

Hydrochloric acid produces __________ when neutralized with a metal.

Match the acid with the type of salt it produces:

What is produced when zinc reacts with sulfuric acid?

Metal oxides and hydroxides react with acids to form salts and gases.

What is the main purpose of a titration?

In a reaction between copper oxide and hydrochloric acid, the product formed is __________.

Match the following substances with their reaction products:

Which of the following acids completely ionises in water?

A pH of 7 indicates an acidic solution.

What happens to the hydrogen ion concentration of a solution when the pH decreases by one unit?

The pH scale ranges from _____ to _____ for measuring acidity and alkalinity.

Match the following acids with their classification:

Acids

Acids form Hydrogen ions (H+) in water
They react with metal carbonates to produce salt, water, and carbon dioxide
They react with metal oxides and hydroxides to form salt and water
They react with insoluble bases to form soluble salts, e.g. reacting copper oxide with hydrochloric acid forms copper chloride
Strong acids completely ionise in water, e.g. hydrochloric acid, nitric acid, and sulfuric acid.
Weak acids only partially ionise in water, e.g. ethanoic acid
The strength of an acid is different from concentration:
- Strength: How much it ionises in water
- Concentration: How much acid is present
The pH scale measures acidity (ranges from 0-14).
- pH 0 is very acidic, pH 7 is neutral, and pH 14 is very alkaline.
- A decrease in pH by one unit indicates a 10 times increase in hydrogen ion concentration.

Alkalis

Alkalis form Hydroxide ions (OH-) in water
They react with acids to form a salt and water, this reaction is called neutralisation.
The ionic equation of neutralisation is H+ + OH- → H2O

Neutralisation

It's the reaction between an acid and an alkali to form a salt and water
It can be demonstrated by titration, which involves:
- Using an indicator (e.g. phenolphthalein or litmus) to determine the endpoint of the reaction
- Repeating titrations for accuracy
Neutralisation is crucial for many industrial processes and biological systems.

Other Reactions

Acids react with metals to produce salt and hydrogen gas
This is a redox reaction:
- The metal is oxidised (loses electrons)
- The hydrogen ions in the acid are reduced (gain electrons)

Universal Indicator

Helps determine the pH of a solution
Changes colour based on the acidity or alkalinity
- It's also available as a pH probe for digital measurements.

Test your understanding of acids and alkalis with this quiz. Explore topics such as ionization, pH scale, and reactions with metals and bases. Perfect for students studying introductory chemistry concepts.