[TEA1]

A solution of the weak base NH3 initially contains 4.25g in 250.0mL of water. Electrical conductivity measurements show that equilibrium 0.42% of the NH3 has reacted with water. What is the Kb of NH3?

I decided to do an ICE chart and used grams of NH3 and mL of water to find Molar which came to be 17M. But I am not sure how to use the Kb equation because then two variables are unknown.  Please let me know if I am on the right track and if this problem can be done this way. Thanks

[AWK]

Solution of NH3 is 1 M not 17 M.

Use Ostwald dilution law

[TEA1]

We did not learn how to do Oswald dilution law.  So there must be a different way to do this problem.

[TEA1]

Ok, So I finally figured out how to this problem.  I did get 1M for NH3.  Just some calculations errors. Thanks