# Chem

What would a titration curve look like for 25 mL of 0.400 M NH3 (aq) with 0.200 M HCl (aq)
-find initial pH
-find 1/2 equivalence point pH and volume of HCl required to reach this point
-find equivalence point pH and volume required to reach this point
-find pH at some volume just past equivalence point.

1. 👍 0
2. 👎 0
3. 👁 158
1. http://www.chemguide.co.uk/physical/acidbaseeqia/phcurves.html
Here are some titration curves. Scroll down to the weak base versus strong acid (there is a curve there where the acid is run INTO the base). Divide the curve up into 4 regions.
A. beginning point.
C. equivalence point.
B. all points between A and B.
D. All points after C.
A. You have a pure weak base. Make an ICE chart, substitute into Kb expression and solve for OH^- and convert to pH.
C. The equivalence point is determined by the salt produced. The equation is
NH3 + HCl ==> NH4Cl
The NH4^+ acts as a Bronsted-Lowry acid and hydrolyzes. Write the hydrolysis equation and make an ICE chart for that, substitute into Kb expression, and solve for H^+, then convert to pH. Many students forget to take into account the dilution of the salt but you need to do that, too.
B. All points between A and B use the Henderson-Hasselbalch equation.
D. All points AFTER the equivalence point are determined by the amount of excess HCl which is a strong acid (it ionizes 100%).
The first think you should do is determine how many mL it takes to reach the equivalence point so you can properly divide the curve into the proper regions.

1. 👍 0
2. 👎 0

## Similar Questions

1. ### Chemistry

Plot the titration of a weak base with a strong acid. Show the titration curve using .106M NH3 and .225M HCl for a 50.00mL sample of the ammonia. No idea where to start here. I'm supposed to plot the curve from 2mL increments

asked by Andrew on October 22, 2014
2. ### Chemistry

When looking at a titration curve, I have to determine which is not true and I have it narrowed down to two options: The initial starting point on the titration curve is where pH depends only on [HA]0 or The finial point on a

asked by Marcus on April 7, 2013
3. ### chem

Calculate the equilibrium concentration of NH3,Cu^2+,[ Cu(NH3)]^2+ ,[Cu(NH3)2]^2+,[Cu(NH3)3]^2+,and[Cu(NH3)4]^2+ in a solution made by mixing 500.0 ml of 3.00 M NH3 with 500.0 ml of 2.00*10^-3 M Cu(NO3)2. The sequential equilibria

asked by jack on November 17, 2015
4. ### Chemistry

When looking at a titration curve, I have to determine which is false and I have it narrowed down to two options: The initial starting point on the titration curve is where pH depends only on [HA]0 or The finial point on a

asked by ramire2 on April 9, 2013
5. ### college chem

The cation M2+ reacts with NH3 to form a series of complex ions as follows: M2+ + NH3 M(NH3)2+ K1 = 102 M(NH3)2+ + NH3 M(NH3)2 2+ K2 = 103 M(NH3)2 2+ + NH3 M(NH3)3 2+ K3 = 102 A 1.0 × 10–3 mol sample of M(NO3)2 is added to 1.0

asked by richard on April 24, 2011
6. ### Chem+ASAP+2 fill in the blank questions+ASAP!!!

PLease check this. They are fill in the blank and I just need to know if they are right. Thanks! 9. Compared to a strong acid-strong base titration curve, a weak acid-strong base titration curve has a (higher, lower) __higher___

asked by David on August 8, 2006
7. ### chemistry, plz check work

NH3+H2S-->NH4HS

asked by Anonymous on March 2, 2009
8. ### Chemistry

Given that 20 ml of a weak acid (HA) was titrated with NaOH and the titration curve of pH vs titrant volume in ml is given, find the initial concentration of the acid? The problem gives the full titration curve starting at pH=2.2

asked by Anonymous on March 21, 2014
9. ### chemisty

Consider the titration of 50 mL of 0.15 M NH3 with 0.1 M HCl. What is the pH at the equivalence point of the titration? (Kb= 1.8X 10-5 Ka= 5.6X10-10)

asked by bert on December 7, 2007
10. ### chem

Consider the titration of 30.0 mL of 0.050 M NH3 with 0.025 M HCl. Calculate the pH after the following volumes of titrant have been added. (The Kb for NH3 is 1.8e-05.) (a) 0 mL . (b) 25.0 mL . (c) 59.0 mL . (d) 60.0 mL (e) 63.0

asked by hannah on March 25, 2013
11. ### chemistry

I am giving a titration curve of a weak base and strong acid. The pH on the y scale is from 0-14 and the volume of titrant in mL is from 0-34. It looks like the equivalene point is around 22? The question is: "The above titration

asked by maura on April 4, 2012

More Similar Questions