m2 - acids/bases

Question 1

strong acids dissociation…
HCl, HNO3, H2SO4

Answer 1

fully, or almost fully, dissociate (fully ionise in solution)
- very good at giving up H+ ions

Question 2

weak acids dissociation…
CH3COOH

Answer 2

only partially dissociate (partially ionise in solution)
- not very good at giving up H+ ions, and once they are released they are quickly taken back again.
- weak acids excellent at accepting these H+ ions back, strong acids are not

Question 3

neutralisation reaction (ions)

Answer 3

H+ + OH- -> H2O

Question 4

generally, acids can be referred to as

Answer 4

HA
H= H+ ion, A= other negative ion eg SO4(2-)
strong acid equation: HA -> H+ + A-
weak acid equation: HA (reversible arrow) H+ + A-

Question 5

concentrated vs dilute acids

Answer 5

concentrated acids have a larger no of acid particles per volume of water
dilute acids have a smaller no of acid particles per volume of water

Question 6

ammonia: weak base

Answer 6

• ammonia gas dissolves in water to form a weak alkaline solution
• dissolved ammonia reacts with H2O

NH3(aq) + H2O(l) ⇌ NH4+(aq) + OH-(aq)

⇌ shows NH3 is a weak base as only a small proportion of the NH3(aq) reacts with H2O

Question 7

ammonium salts

Answer 7

• formed when NH3(aq) reacts with acids
• eg NH3(aq) + HCl -> NH₄Cl(aq)
• eg NH3(aq) + HNO3 -> NH₄NO3(aq)
• eg NH3(aq) + H2SO4 -> (NH₄) ₂SO4

in solution these ammonium salts would actually be found as 2 ions NH4+ and X- (Cl-, NO3-, SO4 2-)

Question 8

amphoteric substances

Answer 8

substances that can act as acids and bases
eg water: H2O -> H3O+ (acting as a base due to accepting a proton)
eg water: H2O -> OH- (acting as an acid due to donating a proton)

eg amino acids