As I am also attaching solution along with the problem there is no point in posting this thread in homework forums . In the following question (solution is also there) https://s29.postimg.org/omlnt73lz/IMG_20170407_090748.jpg https://s18.postimg.org/hsuxm5uvt/IMG_20170407_090805.jpg why are we taking volume= 2 ? I know it's a mixture of two solutions of equal volumes but it's no where mentioned in the question that volume of each solution is 1 litre . Another query regarding the Same problem is that why are we even bothered about the volume?we are directly given the concentrations of Ag and Cl (in the options. just look at the units , it's M that means molarity which is unit of concentration.) If it would have been number of moles then we would have required to divide it by volume to get concentration. Please Clear my doubts.