93. The Ksp of BaCO3 is 1.6x 1 0^-9 . How many moles of
barium carbonate can be dissolved in 3 liters of water?
A. 4 X 10-5 moles
B. 6.9 x 10-5 moles
C. 1.2 x 10-4 moles
D. 2.1 x 10-4 moles
Easy with a calculator...not so easy for me without one.
Can someone help me out with the math?
You need molar solubility (x) and since BaCO3 is an MX (meaning a Metal bonded to something else, called X, and that something else is CO3) so x^2 = Ksp
you should practice taking square roots for scientific notations
the math above is the answer but you need to be able to understand how you get there without a calculator..
So treat each part of the multiplication sign differently:
square root of 16 x 10^-10 will become sqrt(16) * sqrt(10^-10)
which is 4 * 10^-5 realize that every time you take a square root of the power, you just halve the value.
So another example will be : sqrt of 25x10^-40 will be 5x10^-20
When you are doing cube roots, you just divide the power by three:
cube root of
8 x 10^-30 will be
2 x 10^-10
If you are doing 4th root, then divide the power by 4...
So whenever you are taking the n'th root of any number, think about what goes into the number on the left side of the multiplication sign by n times, and divide the power on the right side of the multiplication sign by n.
