science Flashcards
What do state symbols tell us
liquid=(l)
solid=(s)
gas=(g)
aqueous solution=(aq)
all lower case
what are the effects of acid rain
acid rain affects living organisms as well as materials
What is the difference between a chemical and physical change
physical change= no new chemicals formed
reversible
etc. melting = solid-liquid
chemical change = new substances formed
not reversible
etc. reactants-products
What is the reactivity series of metals
- potassium most
sodium - calcium
magnesium
3.aluminisium
4.(carbon)
Z zinc
I iron
T tin
L lead
hydrogen
jewellery
copper
silver
gold
expensive platinum
What is the difference between an acid and a base
acids tend to taste sour
bases tend to taste bitter
litmus paper turns red in acids
litmus paper turns blue in bases
acids contain hydrogen
What happens in a displacement reaction
occurs when a more reactive metal takes place of a less reactive metal
e.g.
potassium+copper nitrate —- potassium nitrate + copper
in the Ph scale what does it mean if it is a reddish colour
strong acid
in the Ph scale what does it mean if the colour is yellow/green
weak acid
in the Ph scale what does it mean if the colour is green/blue
weak base
in the Ph scale what does it mean if the colour is blue/purple
strong base
what numbers are acidic in the Ph scale
1,2,3,4,5,6
What number is neutral in the Ph scale
7
What numbers are alkaline in the Ph scale
8,9,10,11,12,13,14
What happens when acid reacts with metals
see bubbles as hydrogen is made
temperature increases because it is exothermic reaction
more reactive the metal the bigger the increase
What happens in an exothermic reaction
energy is given out to the surroundings
temperature increases
e.g. copper sulfate + water
