So this is a classic M1V1=M2V2 problem, where M is molarity and V is volume and the subsequent numbers represent the two sets of condition (1 being before dilution and 2 being after dilution)
So M1 is going to be 5.0M because it is our initial molarity and V1 is what we are trying to find since we are trying to find how much of initial volume should be diluted.
M2 is 1.30M since it is what molarity is after dilution and M2 is what volume is after dilution which is 50mL.
So M1V1=M2V2 (becomes an algebra problem)
5*V1=1.30*50
V1= 13.0mL
Now this answer should make sense since to dilute something with large molarity to small you only need very few mL than the final volume because you add water to dilute it.
