Question

Transmittance of a solution? Question `3` only

Answer 1

a) `A = 0.118`
b) `a = 0.98 " L " mol^(-1) cm^(-1)`
c) `c = 7.9 *10^(-6)M`

Explanation:

3.a) Use the formula:
`A = 2 - log_10(%T)`
Note: A is the absorbance and %T is the percent of transmittance.
`A = 2 - log_10(76.2)`
`A = 0.118045029`

`A = 0.118`

b) Use the formula:
`A = abc`
Note: A is absorbance, a is molar absorptivity, b is path length, and c is concentration.

`0.118 = a * 1.5cm * 0.0802M`

`a = 0.981255434 " L " mol^(-1) cm^(-1)`

`a = 0.98 " L " mol^(-1) cm^(-1)`

c) `c = A/(ab)`

`c = 0.118/((10000 L/(mol*cm))(1.5 cm))`

`c = 0.00000787 M`

`c = 7.9 *10^(-6)M`