Chemistry - C15 + 20

Question 1

Sulfuric acid

Answer 1

H2SO4

Question 2

Nitric acid

Answer 2

HNO3

Question 3

Ethanoic acid/acetic acid

Answer 3

CH3COOH

Question 4

Phosphoric acid

Answer 4

H3PO4

Question 5

Sodium carbonate

Answer 5

Na2CO3

Question 6

Ammonia

Answer 6

NH3

Question 7

Do acids donate or accept protons to/from a base

Answer 7

Donates to a base

Question 8

Do bases donate or accept protons to/from a acid

Answer 8

Accepts from an acid

Question 9

Acid + reactive metal –>

Answer 9

Salt + hydrogen gas

Question 10

Acid + metal hydroxide –>

Answer 10

salt + water

Question 11

acid + metal carbonate –>

Answer 11

salt + water + carbon dioxide

Question 12

acid + metal hydrogen carbonate –>

Answer 12

salt + water + carbon dioxide

Question 13

acid + metal oxide –>

Answer 13

salt + water

Question 14

end point definition

Answer 14

the point of colour change in the indicator

Question 15

equivalence point definition

Answer 15

amount of standard solution added that is chemically equivalent to the unknown

Question 16

find mass given concentration and volume

Answer 16

1. write equation
2. use n = c x v of known
3. use ratio (eg 1 HCL/1 NaOH) x mols of known found in step 2
4. m = n x molar mass

Question 17

find volume given concentration

Answer 17

1. write equation
2. n = c x v of known
3. ratio eg 1/2 x mols found in step 2
4. v = n/c

Question 18

concentration from mass and volume

Answer 18

c = mass of thing you want to find/(volume x molar mass)

Question 19

simple titration - find concentration

Answer 19

1. write equation
2. determine volume of average titre
3. n(known concentration) = c x average titre volume (convert to LITRES!!)
4. n(unknown concentration) = mol ratio x answer from step 3
5. C(unknown concentration) = answer from step 4/volume of aliquot

Question 20

titration involving dilution - find concentration

Answer 20

1. write equation
2. n(known concentration) = c x volume of aliquot
3. n(unknown concentration) = mol ratio x answer from step 2
4. volume(diluted unknown concentration) = volume when indicator changed colour (given)
5. C(diluted unknown concentration) = n/volume when indicator changed colour (from step 4)
6. dilution factor = final volume (larger number)/original volume (smaller number)
7. undiluted(unknown concentration) = diluted (unknown concentration - step 5) x dilution factor (step 6)