Acids and Alkalis - Chemical Changes Flashcards
What is a base?
Insoluble substance after ph 7
Name the 2 types of bases
- Alkalis - soluble in water
- Insoluble bases - Insoluble in water
What does it mean if a molecule has hydroxide?
It’s an alkali
What happens when an alkali is dissolved in water?
Alkalis ionise into metal ions and hydroxide ions
What is the word equation for neutralisation?
Acid + Alkali –> Soluble salt + Water
What is the ionic symbol equation for neutralisation?
H⁺+ OH⁻ –> H₂O
What ion makes acids acidic?
H⁺
Hydrochloric acid
HCl
Nitric Acid
HNO₃
Sulfuric Acid
H₂SO₄
What happens when acids dissolve in water?
They ionise to non-metals ions and hydrogen ions
Why is excess base added to an acid?
So all the acid reacts
SOLUBLE OR INSOLUBLE
Metal Oxide
Insoluble base
SOLUBLE OR INSOLUBLE
Metal Carbonate
Insoluble
Write the word equation for an acid and carbonate reaction
carbonate + acid –> Salt + Water + Carbon dioxidet
What is a salt?
Non metal + Metal
Write the word equation for an acid and metal
Metal + Acid –> Hydrogen + Salt
Why is HCl a strong acid?
Because every molecule fully ionises in an aqueous solution so they release H⁺ ions. Therefore, a high concentration of H⁺ means a lower pH (more acidic).
What makes an acid weak?
When ions partially ionise in an aqueous solution, the concentration of H⁺ ions are lower, so a higher pH (less acidic) AND if the equation has a reversible sign
Name 3 weak acids
Citric acid, ethanoic acid, Carbonic acid
