Protein x has an absorptivity of 0.4 ml·mg-1 ·cm-1 at 280 nm. What is the absorbance at 280 nm of a 2.0 mg ·ml-1 solution of pro
1 answer:
Absorbance measures the ability of the substance to absorb light at a specific wavelength.
Absorbance is also equal to the product of molar absorptivity, path length and molar concentration.
The mathematical expression is given as:
(1)
where, A = absorbance
= molar absorptivity
l = path length
c = molar concentration.
The above formula is said to Beer's Law.
Absorptivity of protein x =
Path length = 1 cm
Molar concentration =
Put the values in formula (1)
=
Thus, absorbance at 280 nm =
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Answer: -
0.1 ml of bleach should be added to each liter of test solution.
Explanation:-
Let the volume of bleach to be added is B ml.
Density of stock solution = 1.0 g/ml
Mass of stock solution = Volume of stock x density of stock
= B ml x 1.0 g/ml
= B g
Amount of NaOCl in this stock solution = 5% of B g
= x B g
= 0.05 B g
Now each test solution must be added 5 mg/l NaOCl.
Thus each liter of test solution must have 5 mg.
Thus 0.05 B g = 5 mg
= 0.005 g
B =
= 0.1
Thus 0.1 ml of bleach should be added to each liter of test solution.