[urgent]

What would the [OH-] of a solution that has a pOH of 2.7 be?

[OH⁻] = 0.002 M

Explanation:

The definition of pOH is similar to the definition of pH:

This means that with a given pOH value, the calculation of [OH⁻] is a matter of algebra:

To remove the logarithm we increase 10 by the power of the pOH:

"you start with 15.67 g mgco3-xh2o, when heated and all the water is removed, you are left with 7.58 g mgco3 only.

therefore, you had 15.67 - 7.58 = 8.09g h2o  

moles of each :

7.58g mgco3 = ? moles = 7.58g / 83.4g/mole = 0.09moles  

8 09g h2o = ? moles = 8.09g / 18g/mole = 0.44moles  

molar ratio between the two by dividing both numbers by the smallest number :

0.09 / 0.09 = 1  

0.44 / 0.09 = 4.8  

mgco3-5h2o"