One milligram of a compound of molecular weight 160 is dissolved in 10 ml of ethanol, and the solution is poured into a 1-cm uv cell. the uv spectrum is taken, and there is an absorption at = 247 nm. the maximum absorbance at 247 nm is 0.50. calculate the value of for this absorption.

The value of molar absorptivity of the compound is .

Explanation:

Using Beer-Lambert's law :

A = absorbance of solution

C = concentration of solution =

l = path length = 1.00 cm

= molar absorptivity coefficient

Moles of compound =

Volume of the solution = 10 mL = 0.010 L

A = 0.50 , l = 1 cm

The value of molar absorptivity of the compound is .

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !

personal, she chose to do it.