Nough of a monoprotic acid is dissolved in water to produce a 0.0199 M solution. The pH of the resulting solution is 2.64 . Calculate the K a for the acid.

Explanation

pH = 2.64

pH = - log [H+]

[H+] = 0.00229 M

HA = 0.0199 M

Dissociation equation

HA --> H+ + A-

Ka = [H+][A-]/[HA]

[H+] = [A-]

Ka = (0.00229^2)/0.0199

= 2.64 × 10^-4 M

- decrease the number of plants and animals living in the water.

"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"