Chemistry Term 2

Coefficients

Numbers placed in front of chemical formulas

Subscript

Small number for the number of atoms in the elements

States of matter: (s), (l), (g), (aq)

S = solid

L = liquid

G = liquid

Aq = aqueous solution

What does the law of conservation of mass state

Matter is neither created or destroyed

Acids

Have a pH of less then seven

Tastes sour

Turns litmus paper red

Releases hydrogen ions when dissolved in water

Bases

Have a pH of greater than seven

Tastes bitter

Turns litmus paper blue

Feels soapy

Substances that produces hydroxide ions when dissolved in water

Alkali

A soluble base

Dissolves in water to form an alkali solution

Salt production

Salts are ionic compounds

They consist of positively charged cations and negatively charged anions making then electrically neutral

Sulfuric acid =

Sulfate salt

Hydrochloric acid =

Chloride salt

Nitric acid

Nitrate salt

Phosphoric acid

Phosphate salt

Neutralisation

Involves an acid reacting with a base or an alkali

Base can be: Metal oxides, metal hydroxides

Base + acid reacts to produce

A salt + water

Combustion reactions

Require oxygen and a fuel

Displacement reaction

Displacing one type of atom with another

A + BC —→ AC + B

Acids react with metals to form

Salt + hydrogen

Observations of a reaction between acids and metals

Bubbles or fizzing due to hydrogen gas being released

The metal gradually dissolving

The solution warming up (exothermic)

What is the product of an acid and carbonate

Acid + carbonate —→ water +carbon dioxide + salt

Testing for carbon dioxide

Limewater turns milky

A lit splint will be extinguished