# chemistry

posted by .

What is the pH for the solution made from 11.10 mL of 0.278 M HCl solution mixed with 70.90 mL of 0.1300 M ammonia solution ? Note that the pKa for NH4+ is 9.241

8.94
9.24
8.77
9.72
9.54

• chemistry -

hey i found the working to this somewhere else and it was

its a buffer so
pH=pKa + log[base]/[acid]

=9.241 + log [70.9x.1300]/[11.1x0.278]

= 9.72

which makes sense but...
i also had that question on my assignment and got it wrong

i cannot find a reason for this but as we were told not to use that eqn in chem then there must be another way to do it

• chemistry -

calculate the percent composition for NaOH and the tell how many grams of each elements are in a 14 gram sample.

## Similar Questions

1. ### chemistry

Q.1 What will be the pH at the equivalence point during the titration of a 100 ml 0.2M solution of CH3COONa with 0.2M of solution of HCl?
2. ### Chemistry

A 100 milliliter sample of 0.100-molar NH4Cl solution was added to 80 milliliters of a 0.200-molar solution of NH3. The value of Kb for ammonia is 1.79 x 10^-5. (a) What is the value of pKb for ammonia?
3. ### Chemistry

A 100 milliliter sample of 0.100-molar NH4Cl solution was added to 80 milliliters of a 0.200-molar solution of NH3. The value of Kb for ammonia is 1.79 x 10^-5. (a) What is the value of pKb for ammonia?
4. ### Chemistry

I have no idea what to do here.... What is the pH for the solution made from 11.10 mL of 0.2780 M NaOH solution mixed with 70.20 mL of 0.1300 M ammonium chloride solution?
5. ### college cemistry

What is the pH for the solution made from 11.10 mL of 0.278 M HCl solution mixed with 70.90 mL of 0.1300 M ammonia solution ?
6. ### chem

what is the pH for the solution made from 11.1 mL of 0.278M NaOH solution mixed with 70.2mL of 0.13M ammonium chloride solution?
7. ### chemistry

If you mixed equal volume of .1 M HCl and .20 M Tris (pka=8.3), IS THE RESULTING SOLUTION A BUFFER SOLUTION?
8. ### Chemistry

A 51.46 mL sample of an ammonia solution is analyzed by titration with HCl. The reaction is given below. NH3(aq) + H+(aq) NH4+(aq) It took 38.57 mL of 0.0984 M HCl to titrate (react completely with) the ammonia. What is the concentration …
9. ### Chemistry

What is the Ph for the solution made from 11.10mL of 0.278M HCL solution mixed with 70.90mL of 0.1300M ammonia solution?
10. ### Chemistry - Science (Dr. Bob222)

Ammonia is a weak base with a Kb of 1.8 x 10-5. A 100.0 mL sample of 0.13 M aqueous solution of ammonia (NH3) is mixed with 87 mL of 0.15 M solution of the strong acid HCl, calculate the pH of the final solution. A) 2.9 B) 11.1 C) …

More Similar Questions