Acid/Base Equilibria

Question 1

what is the bronsted-lowry definition of an

1) acid
2) base

Answer 1

1) according to the bronsted-lowry theory, an acid is a proton (H+) donor
2) according to the bronsted-lowry theory, a base is a proton (H+) acceptor

Question 2

what does the term ‘conjugate’ mean?

Answer 2

related to each other by the difference of a proton

Question 3

what is a strong acid?

what is a strong base?

Answer 3

1) a proton donor that donates ALL its protons(H+)

2) a proton acceptor that donates ALL protons(H+)

Question 4

what is a weak acid?

what is a weak base?

Answer 4

1) a proton donor that only donates SOME protons(H+)

2) a proton acceptor than only accepts SOME protons(H+)

Question 5

how does the Ka value of an acid relate to its strength?

how does the pKa value of an acid relate to its strength?

Answer 5

the stronger the acid, the larger the Ka value

the stronger the acid, the smaller the pKa value

Question 6

how does the Kb value of a base relate to its strength?

how does the pKb value of a base relate to its strength?

Answer 6

the stronger the base, the larger the Kb value

the stronger the base, the smaller the pKb value

Question 7

if given the pH of an acid, how do you find the concentration of the hydrogen ion in the acid?

Answer 7

[H+]= log inverse (-pH)

Question 8

at what pH does the colour of the following indicators change?

• methyl orange
• litmus
• bromothymol blue
• phenolphthalein

Answer 8

methyl orange- 3.1-4.4: red to yellow
litmus- 5.5-7.5: red to blue
bromothymol blue- 6.0-7.6: yellow to blue
phenolphthalein- 8.0-9.8: colourless to pink