1What is released into solution when acid dissolves in water?
hydrogen ions as protons (H+)
2What makes an acid strong?
complete dissociation
3What makes an acid weak?
partial dissociation
4What is meant by complete dissociation?
acid releasing all its H atoms into solution as H+ ions
5What is meant by partial dissociation?
acid releases small proportion of available hydrogen atoms as H+ ions into solution
6Are most organic acids weak or strong?
weak
7What is a base?
substance that neutralises acid to form salt
8What is an alkali?
base that dissolves in water, releasing hydroxide ions (OH-) into solution
9What substances are classified as bases?
-metal oxides
-metal hydroxides
-metal carbonates
-ammonia
10Acid + Metal oxide/ hydroxide ->
salt + water
11Metal carbonate + acid ->
salt + water + carbon dioxide
12What can titration be used for? (3)
-find concentration of solution
-identify unknown chemicals
-find purity of substance
13Why is checking purity important as quality control?
tiny impurity could cause harm in food, medicine and cosmetics
14What is a standard solution?
solution of known concentration
15What is a volumetric flask used for?
make up standard solution very accurately
16Burette reading recorded to nearest.....
half division
17Where on the meniscus do you measure from?
bottom
18
What is the titre?
volume of solution added from burette
19What 3 things will you know after titration?
-reacting volume of one solution
-concentration and reacting volume of other solution
20What is an oxidation number?
number of electrons imvolved in bonding to different element
21What is the oxidation number for elements?
0
22What happens to the oxidation number during oxidation?
increase
23What happens to the oxidation number during reduction?
decrease