Calculate the PH of each of the following solutions?
By wellinformed
@wellinformed (72)
China
March 3, 2009 11:22pm CST
a. 0.22 M CH3NH3C21
b. 0.047 M NaCH
c. 0.31 M Na2C03 (Consider only the reaction of CO32 -+ H20 reverse reaction arrow HC03-+OH-)
d. 0.15 M KN02
e. 0.46 M NH4Br
Please help and explain.
Please help with my other questions as well.
2 responses
@Uroborus (908)
• Canada
31 Mar 09
Well, I'm not going to do the calculation for you but I will give you some comments.
a. For CH3NH3C21, you would have to give whether it's an acid or base, hard to tell from the formula. It also looks like the formula you gave is wrong, 21 carbons seem like a lot for this type of chemical.Also you have to give the Ka or Kb if they exist, otherwise you can't do the calculation.
b. Did you mean NaOH for this? There is no such thing as NaCH.
c. This one can be done. I assume you mean the the reaction shown on the attached image. You need to look up the Kb1 of carbonate ion. The use the equilibrium constant. Thta's as far as I'll go.
d. This is similar to the c. Write down the hydrolysis formula for NO2 (it does hydrolyse since HNO2 is a weak acid). Then look up the Kb of NO2 and solve using the equilibrium constant formula (like in c).
e. In this case the NH4+ ion hydrolyses. Look up it's Ka and use equlibrium constant formula.
Hope this helps
