HELP PLEASE! Can you please answer these questions with detailed steps. I am con

Question

HELP PLEASE! Can you please answer these questions with detailed steps. I am confused and really trying to understand this. Thanks!

Available information on coffee:

Substance description: White crystalline powder

Molecular formula: C6H10N4O2

PH of coffee in pot: 7.1

Volume of coffee pot: 300ml

If caffeine hydrochloride, the salt of caffeine, is added to coffee. What will happen to the following equilibrium, will it shift to the right, left or not be affected? Why and what is this effect called? Kb= 5.3x10-14   C8H10N4O2 + H2O HC8H10N4O2+ + OH-

Could the caffeine/caffeine hydrochloride pair act as a buffer? Explain why or why not?

A 50ml sample of the coffee pot was sent to be analysed for the amount of caffeine by titration. The sample needed 100.0ml of 0.15M HCl to neutralize the caffeine, which was a weak base. Write the balanced reaction between the caffeine and the HCl

Calculate the molarity of the caffeine in the sample

Calculate the number of grams of caffeine consumed by Mark according to this data

Calculate the initial PH, the PH at the equivalence point and the ph after an additional amount determined by you, is added to complete a titration curve (Hint: weak base + strong acid, Vtotal=?)

Sketch the titration curve that would result, labelling all axes.

Which indicator would be right to use for this titration and why?

Explanation / Answer

C8H10N4O2 + H2O HC8H10N4O2+ + OH-

C8H10N4O2 + HCl HC8H10N4O2+ + Cl-[ 100% dissociation]

a) K Value of weak base is attached by addition of either the cojugated acid or base

b) It reduces degree of dissociation by addition of caffeine HCL containing common ion caffeine

c) shift in left side reaction in an ionic equilibrium it reducess the concentration of common ion

2) this effect is known as common ion effect

3)yes it act as a buffer bcoz when caffeine (weak base and it salt caffeine HCL ) acts as a buffer

4) M1V1 = M2V2 M1 V1= molarity of caffeine and volume of caffeine M2V2 = Molarity and volume of HClby calculating with this the m1 found to be 0.3M

5) amount present = Titer value X equivalent weight factor X Actual molarity/ expected molarity

TV = 100

Equivalent factor 0.0291

actual and expected molarity =0.15

and by above calculation we got 2.91g/50ml of solution

6)balanced equation was already given above

7)initial pH

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