Question

The mass of the coloured compound in the same solution as in question 1 above that would have an absorbance of 1.5 in the same 1.00 cm cell is (in grams):

	a.	0.050
	b.	0.075 log10 2
	c.	0.033 log10 2
	d.	0.075 / log10 2
	e.	0.075 / log10 0.5
	f.	none of the above

Answer 1

Solution:

1) solution for question posted in comments,

by beer lambert law we know,

A = Ecl --> l = A/Ec

A= log(Io/I)= 75% = 0.75

l = (0.75) / (1)(0.05/0.1)

= 0.75/0.5

= 1.5 cm approx can be taken as 2.0 cm

2) for the second one A = 1.5 given and l=1 cm for 100 ml solution, we have to find the mass in grams the equation of beer-lambert on rearrangement becomes,

c = A/El = 1.5/(1)(1) = 1.5

(mass/vol) =c = 1.5

(mass/0.1) = 1.5

mass = 1.5*0.1 = 0.15 g

There is no option for this, so the answer is Option (f) none of the above