Two questions I am confused on and office hours didn't help me.
(1) If a solution of [Mo(NH3)6]Cl3 has an absorbance of 1.21 when measured in a cell with a path length of 1.20cm, what is its concentration? The molar absoptivity at the wavelength at which the measurement was obtained is 130 M-1 cm -1.
(2) What is the Ni2+ concentration of a solution prepared by adding 25.0 mL of 0.0400 M Ni2+ to 30.0 mL of water?
2006-10-17 04:16:10 · 2 answers · asked by ibrakeforchucknorris 1 in Science & Mathematics ➔ Chemistry
Its been a little while since i took these classes but I am pretty sure there is a simple formula for question one. Just plug i nthe variables and you should be able to solve it just remeber to use the right units.
Absorbance = path length* absorbtivity* Concentration
just rearange and solve for concentration
2) first calculate how many moles of Ni2 you have by first converting 25 ml to liters. then multiple by the molarity. then divide that number of moles by your new total amount of water, which will now be 55 ml, remeber to convert everything into liters though oryou will get the wrong answer.
2006-10-17 04:30:02 · answer #1 · answered by abcdefghijk 4 · 0⤊ 0⤋
1. should be: A= elc
2. use m1v1=m2v2: ( 0.0400)(25.0ml)=m2(55ml)=
1=55m2= 0.0182M
2006-10-17 11:53:44 · answer #2 · answered by loveboatcaptain 5 · 0⤊ 0⤋