In the test for control of absorbance in UV calibration why
do we use only potassium dichromate and what is purpose of
taking a specified amount of 57.0-63.0mg?
Answers were Sorted based on User's Feedback
Answer / bhagya lakshmi.k
It will show max absorbance in Ultraviolet region (200-
400nm) (i.e) at 235,257,313,350 nm
| Is This Answer Correct ? | 53 Yes | 4 No |
Answer / sunil.m.kulkarni ( avon/arch p
Potassium Dichromate - UV Absorbance and Linearity
Product Description:
The use of potassium dichromate solvated in dilute
perchloric acid or suplhuric acid is an established and
well recognised method for the validation of the absorbance
scale and linearity of a spectrophotometer in the UV
region.
When prepared in 0.001M perchloric /Suplhuric acid,
potassium dichromate solution gives a spectral scan
containing characteristic peaks at 257 nm and 350 nm, and
troughs at 235 nm and 313 nm. Within the concentration
range 20-100 mg/l, if the absorbance scale of a narrow SBW
(< 2 nm) spectrophotometer is linear, the apparent
absorbances of a series of concentrations will be a linear
function of concentration.
Note: Primary standard ( Extra pure potassium dichromte
after drying to be used for calibration ) 57-63mg in -
1000ml concentration is perfect concentration for achiving
perfect charecteristic peak and throughs
| Is This Answer Correct ? | 36 Yes | 5 No |
Answer / sagadevan
becoz of photochemical stability,so on prolonged exposure to uv light the absorbance own not change,
| Is This Answer Correct ? | 18 Yes | 4 No |
Answer / devidas
it show the maxima at 235nm,257nm,313nm, and 350nm in UV
region. and it consider as a primary standard which is high
purity
| Is This Answer Correct ? | 18 Yes | 7 No |
Answer / vivek
we are use potassium dichromate for the verification of spectrophotometer because it show maximum absorbtion in uv region...
| Is This Answer Correct ? | 12 Yes | 5 No |
Answer / srinathsagar
UV range is 190-400nm so in this range potassium dichromate with sulfuric acid gives characteristic peaks(At 235,257,313 and 350nm)
| Is This Answer Correct ? | 4 Yes | 1 No |
because it covers uv to visible region i.e. 235nm,257nm,313nm,350nm
| Is This Answer Correct ? | 6 Yes | 4 No |
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