ACIDS AND BASES Flashcards
What are the properties of acids?
- Corrosive
- Sour tasting
- reacts with metals
- neutralises effects of bases
- releases H+ ions in solutions
What are examples of acids?
- Hydrochloric acid
- citric acid
- lactic acid
- carbonic acid
What makes an acid strong or weak?
The strength of an acid depends on how easily it can donate it’s hydrogen ions (H+)
What are the properties of bases?
- Taste bitter
- can burn
- neutralise effects of acids
- releases OH- ions in solution
What are examples of bases?
- sodium hydroxide
- sodium bicarbonate
- toothpaste
What makes a base strong or weak?
Strong bases produces lots of hydroxide ions (OH-) in solution. Weak bases produces only a few OH- ions.
What is another word for a base?
alkali
What is a universal indicator?
A universal indicator indicates whether a substance is an acid or a base. There are two main types of universal indicators: litmus paper and the universal indicator.
When the litmus paper turns red it means it is an acid and when it turns blue it means it is a base.
When the universal indicator turns red it means it is an acid and when it turns purple it is a base. Red means it is a strong acid, orange to yellow means it is a weak acid, green means it is neutral, dark blue means weak base and purple means strong base.
What is the pH scale?
A scale from 0-14 that tells you how acidic or basic a solution is.
What pH are acidic, neutral and basic substances
- Strong acid: Have a pH of 1 to 2
- Acidic Solutions: Have a pH less than 7
- Neutral solutions: Have a pH of 7
- Basic Solutions: Have a pH more than 7
- Strong base: Have a pH of 12 to 14
How can we change the pH of a substance?
- To make an acid become neutral you add water .
- To make a base become neutral you add water
- This process is called neutralisation
What ion do acidic substances release?
H+ ions
What ion do basic substances release?
OH- ions
What is special about water and the ions it releases?
Water is neutral so it releases both H+ and OH- ions
Name a commonly used strong acid
Hydrochloric acid
Name a commonly used strong Base
Sodium Hydroxide
What products are formed when you react a metal with an acid?
Salt + hydrogen
Worded equation for different metal + dilute acids. Give an example using the metal zinc and nitric acid.
Equation:
metal + dilute acid → salt + hydrogen.
Example:
Zinc + nitric acid → zinc nitrate + hydrogen
What is a neutralisation reaction?
It is a reaction where an acid and a base react together to form water (pH of 7: neutral)
What products are formed when there is a neutralisation reaction?
salt + water
Worded equation for different bases + acids. Give an example using hydrochloric acid and the base sodium hydroxide.
Equation:
Acid + base → salt + water.
Example:
Hydrochloric acid + sodium hydroxide → sodium chloride + water
What are some harmful effects of ocean acidification?
- it reduces the amount of carbonate in the water.
- makes it difficult for organisms to form shells
existing shells can dissolve because of the acid
What is ocean acidification?
Ocean acidification is when the amount of carbon dioxide increases because the ocean absorbs it. A chemical reaction occurs causing the water to become more acidic.
What is acid rain
Large amounts of waste gases from industry and motor vehicles are making rain more acidic than normal.
