Acids and Alkalis
description
Transcript of Acids and Alkalis
![Page 1: Acids and Alkalis](https://reader036.fdocuments.us/reader036/viewer/2022062302/56816675550346895dda1028/html5/thumbnails/1.jpg)
Acids and Alkalis
Learning Objectives
• To know that solutions can be sorted by whether they are: acid, alkali or neutral.
• To understand that an alkali reacts with an acid to cancel it out.
• To know that indicators show you how acidic
or alkaline a solution is.
![Page 2: Acids and Alkalis](https://reader036.fdocuments.us/reader036/viewer/2022062302/56816675550346895dda1028/html5/thumbnails/2.jpg)
Acids and alkalis
Solutions can be sorted by whether they are: acid, alkali or neutral.
When a substance dissolves in water it makes a solution.
![Page 3: Acids and Alkalis](https://reader036.fdocuments.us/reader036/viewer/2022062302/56816675550346895dda1028/html5/thumbnails/3.jpg)
When the oxide of some non-metals dissolve in water they make an acid.
• have a sour taste. • are corrosive to metals.
• Excess of H+ ions
Acids
Characteristics:
Formed:
![Page 4: Acids and Alkalis](https://reader036.fdocuments.us/reader036/viewer/2022062302/56816675550346895dda1028/html5/thumbnails/4.jpg)
Acids react with metals
![Page 5: Acids and Alkalis](https://reader036.fdocuments.us/reader036/viewer/2022062302/56816675550346895dda1028/html5/thumbnails/5.jpg)
Acids
• Lemon juice • vinegar• hydrochloric acid • sulphuric acid and nitric acid• citric acid
There are many acids present in our everyday lives.
![Page 6: Acids and Alkalis](https://reader036.fdocuments.us/reader036/viewer/2022062302/56816675550346895dda1028/html5/thumbnails/6.jpg)
Neutralization
• Acids and alkalis react with each other. The alkali cancels out the acid in the reaction.
![Page 7: Acids and Alkalis](https://reader036.fdocuments.us/reader036/viewer/2022062302/56816675550346895dda1028/html5/thumbnails/7.jpg)
Alkalis
When metals dissolve in water they make an alkali solution.
• feel soapy. • are corrosive.• Excess of OH- ions
![Page 8: Acids and Alkalis](https://reader036.fdocuments.us/reader036/viewer/2022062302/56816675550346895dda1028/html5/thumbnails/8.jpg)
Alkalis
Alkalis are present in many cleaning substances in use in our homes.
• Kitchen cleaners• Ammonia• sodium hydroxide, which attack
grease.
![Page 9: Acids and Alkalis](https://reader036.fdocuments.us/reader036/viewer/2022062302/56816675550346895dda1028/html5/thumbnails/9.jpg)
Indicators
They change color in acid or alkaline solutions.
Indicators change color in the presence of certain molecules
![Page 10: Acids and Alkalis](https://reader036.fdocuments.us/reader036/viewer/2022062302/56816675550346895dda1028/html5/thumbnails/10.jpg)
LitmusTest
• Turns red in an acid. • Turns blue in an alkali.
![Page 11: Acids and Alkalis](https://reader036.fdocuments.us/reader036/viewer/2022062302/56816675550346895dda1028/html5/thumbnails/11.jpg)
Universal Indicator• Universal indicator changes color in
acids and alkalis, and measures the strength of the acid or alkali.
ACIDS ALKALIS
Neutral
![Page 12: Acids and Alkalis](https://reader036.fdocuments.us/reader036/viewer/2022062302/56816675550346895dda1028/html5/thumbnails/12.jpg)
The pH scale
![Page 13: Acids and Alkalis](https://reader036.fdocuments.us/reader036/viewer/2022062302/56816675550346895dda1028/html5/thumbnails/13.jpg)
Applications of Neutralization
• Indigestion: Our stomach carries around hydrochloric acid. Too much of this leads to indigestion. To cure indigestion, you can neutralize the
excess acid with baking soda or specialized indigestion tablets.
• Insect Stings Bee stings are acidic and can be neutralized with baking soda (bicarbonate of soda). Wasp stings are alkaline and can be neutralized with vinegar.
![Page 14: Acids and Alkalis](https://reader036.fdocuments.us/reader036/viewer/2022062302/56816675550346895dda1028/html5/thumbnails/14.jpg)
More Applications of Neutralization
Factory Waste: Liquid waste from factories is often acidic. If it reaches a river it will destroy and kill sea life of many forms. Neutralizing the waste with slaked lime can prevent this.
Soil Treatment: When soils are too acidic (often as a result of acid rain) they can be treated
with slaked lime, chalk or quicklime, all alkalis. Plants
and crops grow best in neutral soils.