Dilutions Problems

[Matia Kim 1B]

I've been struggling to figure out if a question is asking for a dilutions solutions or convergence solution. I know you need 3 givens to answer a dilutions but some questions have you figure out the third solution. What should I be looking for to know whether if the question is asking for a dilutions solution or not?

[Clarissa Nava 3H]

You should look for molairty or in other words the moles of solute per solution. to dilute a stock solution. and then from there the M1V1=M2V2 equation would be used. [quote="Matia Kim 1B"]

[isarose0]

In question G5, once you are solving for the volume needed to obtain 2.15 mmil of Na+ why do you need to divide by 2 mol of Na+?

[Timothy_Yueh_4L]

@isarose00 When Na2CO3 dissociates in water the balanced equation is: Na2CO3 --> 2Na^+ + CO3^2-, thus showing that it takes 2 moles of sodium ions to produce one mole of sodium carbonate, hence the division by 2.