Question

Regarding previous post: I don't understand what I'm doing. My book says the answer is .50 M Ba(NO3)2 but I'm not getting that.

Answer 1

You didn't tell me your answer but I'll bet is is 1 M Ba(NO3)2. You're forgetting the dilution of each of the reagents by each other. You should have 1 mole Ba(NO3)2 left over and that in 2 L is 0.5 M. Is that what you're doing?

Answer 2

Dr Bob is right: you have 1 mole Ba(NO3)2 in two liters of solution, that is by definitiona, .5M

Answer 3

i made a mistake along the way but i cant find it to fix it. should i have done 4 mol/2 L instead of 2 mole/1 L

Answer 4

No.
2AgNO3 + BaCl2 ==> 2AgCl + Ba(NO3)2

2 x 1 = 2 moles AgNO3
2 x 1 = 2 moles BaCl2
AgNO3 is limiting; that is
2 moles AgNO3 will use 1 mole BaCl2.
At equilibrium,
All of the AgNO3 has been used.
BaCl2 = 2 moles initially - 1 mole reacted = 1 mole remaining.
1 mole/2L = 0.5 M.