Acids and Bases- Week 6

Question 1

Where will a reaction proceed given its Keq value?

Answer 1

If Keq> 1 product favoured
if Keq< 1 reactant favoured

Question 2

what will be the integer of free energy (G) and enthalpy (H) if a reaction proceeds to products?

Answer 2

• negative
• reaction is exothermic/exergonic

Question 3

What will the integer of entropy (s) if the reaction proceeds to products

Answer 3

positive

Question 4

What effect will a catalyst have on the activation energy

Answer 4

it will lower the value of double dagger g but doesn’t effect on free energy

Question 5

If an acid is strong, will the reaction proceed to the left or right? Why?

Answer 5

It will proceed to the right, to the products side because delta G (free energy) is < 0

Question 6

What is the correlation between pKa value, the strength of the acid and where the reaction will proceed?

Answer 6

the lower the pKa value, the stronger the acid.
The equilibrium of the solution will lie in the direction of the weaker acid

Question 7

How can you determine acid strength?

Answer 7

Electronegativity: If the base that is carrying the negative charge is more electronegative, the acid will be stronger
Atomic size: the H beside the bigger atom is more acidic
Induction: if the atoms near the negative charge are larger and a better electron acceptor, this will stabilize charges and create a stronger acid

Question 8

Formula for Formal charge

Answer 8

Valence Electrons- non-bonded electrons- [bonded electrons/2]