acids and bases

Question 1

acids

Answer 1

a substance that produces H+ ions
in a solutions their pH is <7
HCl, HNO3, N3PO4, H2SO4 all produce h+ ions in water

Question 2

non- metal oxides e.g. CO2

Answer 2

CO2 + H2O —> H2CO3
H2CO3 —> 2H+ + CO3 2-

Question 3

bases

Answer 3

metal oxides, metal hydroxides, metal carbonates, ammonia
substances that react with acids to create water

Question 4

alkali

Answer 4

a base that dissolve in water
gp 1 hydroxides/ carbonates
the pH scale only measures substances that are dissolved in water

Question 5

neutralization

Answer 5

a reaction of an acid and a base to produce water
proton transfer reaction

Question 6

consentration

Answer 6

measures the moles of a solute dissolved in a specific volume of solvent

Question 7

conc. of an acid

Answer 7

a measure of the no. of mols dissolved in water. any acid can have any concentration

Question 8

what does the strength of an acid depend on

Answer 8

degree of dissociation

Question 9

e.g. of strong and weak acid

Answer 9

strong acid- HCL
weak acid- ethanoic acid (XH)

Question 10

what do the properties of an acid depend on

Answer 10

on the H+

Question 11

HCL and XH reaction with Mg

Answer 11

HCL- hotter produce same vol. of H2 effervesces faster
CH3COOH - less hotter, same vol. of H2, effervesces

Question 12

HCL and XH reaction with Na2CO3

Answer 12

HCL- no temp change, produce same vol. of H2, effervesces faster
CH3COOH- no temp. change, produce same vol. of H2, effervesces

Question 13

HCL and XH reaction with NaOH

Answer 13

HCL- hotter
CH3COOH- less hotter

Question 14

electrical conductivity with HCL and XH

Answer 14

HCL- effervesces at electrodes, 4amps
CH3COOH- effervesces electrodes, 2amps

Question 15

titration

Answer 15

a method use to accurately determine the conc. of an acid or base

Question 16

volumetric pipette

Answer 16

measure a specific volume very accurately

Question 17

burette

Answer 17

measure a range of volumes less accurately

Question 18

titration method

Answer 18

1. clean pipette with water
2. clean pipette with intended chemical
3. measure 25cm3 of unknown solution into a conical flask
4. add 2 drops of indicator
5. clean burette with water and intended chemical
6. fill burette with acid
7. clamp vertically
8. measure intial vol.
9. add acid until solution turns colourless

Question 19

methyl orange

Answer 19

acid- red
base- yellow

Question 20

phenolphthalein

Answer 20

acid- colorless
base- pink

Question 21

salt

Answer 21

an ionic compound that can be formed by the reaction of an acid

Question 22

properties of salts

Answer 22

high melting point due to strong electrostatic forces
conduct elec. as (aq) and (l) bc ions can move and carry charge
soluble in water

Question 23

solubility rules

Answer 23

all nitrates are soluble
all gp 1 compounds are soluble
all halides are soluble except with ag or Pb 2+
all sulfates are soluble except with Ca, Sr, Ba, Pb, Ra
all hydroxides, oxides, and carbonates are insoluble

Question 24

precipitation

Answer 24

2 solutions reacting to form a solid

Question 25

displacement

Answer 25

when a more reactive element replaces a less reactive one in its compound

Question 26

how do you produce a salt that is pure

Answer 26

the base in the reacvtion need to be insoluble

Question 27

method for salt preperation

Answer 27

1. measure xcm3 of acid in a conical flask
2. add excess base until solid no longer dissapears
3. heat to speed reaction
4. filter mixture into concial flask
5. heat filtrate on hot plate until 3/4 of water has evaporated
6. leave to crystallize
7. filter to remove excess water
8. collect residue