 So, let's do a beer's law, an actual beer's law problem this time. It says a 0.100 mole per decimeter cubed aqueous solution of nickel-2 salt shows three absorbances, one of which has a value, a molar absorptivity value, of 2.95 decimeter cubed per mole per centimeter. What is the corresponding absorbance if the path length of the solution cell used for the measurement is 1.00 centimeters? Okay? So, hopefully you see we've got all of this stuff written up here, concentration value, moles per decimeter cubed, molar absorptivity, 2.9 decimeter cubed per mole per centimeter, and path length is B at 1.00 centimeter. Remember beer's law is A equals epsilon BC. So, we have all of these units in here. So, we're looking for absorbance. So, it's just plug them in, okay? So, A is going to be epsilon. I like to write it so I can cancel my units out. So, I'm going to write it like this. 2.95 decimeter cubed per one mole times centimeter. Okay? So, that's epsilon, molar absorptivity, the path length, 1.00 centimeters, and the concentration is 0.100 moles per one decimeter cubed. So, hopefully you can see here we want to cancel out our units. Hopefully we get no units at the end because absorbance has no units. So, moles, cancels with moles, centimeters with centimeters, decimeter cubed with decimeter cubed. Okay? So, all we have to do now is get our calculator and plug it in. 2.95 times 1 times 1. We don't have to know why I did that. So, to 3, syncing, 0.295. So, again, no units for absorption. So, the absorbance of this solution is going to be 0.295. Any questions on this one? Ask now or forever. Hold your piece. Okay.