What does this symbol mean ?…
- Oxidising
- Provides O2 which allows materials to burn mor fiercely
- E.g. Liquid oxygen
What does this symbol mean ?…
- Highly Flammable
- Catches fire easily
- E.g. Petrol
What does this symbol mean ?…
- Toxic
- Can cause death either by swallowing or breathing in, or absorption through skin
- E.g. Hydrogen cyanide
What does this symbol mean ?…
- Harmful
- Like toxic but not quite as dangerous
- E.g. Copper sulfate
What does this symbol mean ?…
- Irritant
- Not as corrosive but can cause redding or blistering of the skin
- E.g. Bleach
What does this symbol mean ?…
- Corrosive
- Attacks and destroys living tissues including eyes and skin
- E.g. Concentrated sulfuric acid
What is an acid ?
A substance at pH 0 to 6
E.g. Vinegar, Acid rain, Normal rain, Lemon juice
Red to yellow on the universal indicator
What is a neutral ?
pH 7
E.g. Pure water
Green on the universal indicator
What is a Alkali?
A base at pH 8 to 14
E.g. Ammonia, Oven cleaner
Blue to purple on the universal indicator
What is the equation for a neutralisation reaction ?
Acid + Base > Salt + Water
What acid does your stomach produce and what is it’s use?
HCl - Hydrochloric acid
Helps with digestion and kills bacteria
Indegestion is caused by too much HCl and bases in tablets neutralise the excess acid
What 2 types ofmetals are usually indegestion remedies?
- Mydroxides
- Carbonates
What to metal hydroxide/oxides produce when reacted with an acid?
Salt + Water
What to metal carbonates produce when reacted with an acid?
Salt + Water + Carbon Dioxide
How do you work out thesalt which is produced during a Acid + Base = Salt + water reaction ?
Hydrochloric acid + _*coppe*r_ oxide = copperchloride + water
Sulfuric acid + zinc*** oxide = ***zinc sulfate + water
Nitric acid + Magnesium*** oxide = ***Magnesium nitrate + water
What does electrolysis mean ?
The breaking down (decomposition) of a compound using electrical energy
Splitting up electricty
What does electrolysis need ?
- Direct current (D.C.)
- A liquid to conduct the electricity
- two electrodes
If you use Electroylsis to break down HCl what are the two components you get?
- Hydrogen gas (H2)
- Chlorine gas (Cl2)
What is the test for Hydrogen?
- A lighted splint into a test tube with the gas
- If hydrogen is present you will hear a squeaky pop
What is the test for chlorine?
Into a solution in a test tube put in damp litmus paper
It will turn white if chlorine is present
And it may breifly turn red as chlorine is acidic
What is the test for oxygen ?
Checking if the gas in a test tube relights a glowing splint
What does the electrolysis of salt produce and what are its uses?
- Chlorine
Uses of chlorine:
- Treat water suplies by killing bacteria and other microorganisms
- Manufacture bleach
- Make the polymer - poly(chloroethene) - PVC
What does the electroylsis of Water produce?
Hydrogen gas
Oxygen gas
