chemistry

What is the Ka of a weak acid (HA) that produces a pH of 3.45 with 0.1M?
2.54E-3
3.45E-3
1.27E-6
3.56E-3
5.48E-4

1. 👍 0
2. 👎 0
3. 👁 112
1. pH = 3.45
3.45 = -log(H^+)
(H^+) = approx 3.55E-4.
...........HA ==> H^+ + A^-
I.........0.1.....0.....0
C..........-x.....x.....x
E.........0.1-x...x.....x
where x = 3.55E-4
Substitute that into Ka expression and solve for Ka.

1. 👍 0
2. 👎 0

Similar Questions

1. SCIENCE PLZZ HELP!!!

Given equal concentrations, which of the following produces the fewest hydronium ions in an aqueous solution? strong acid weak acid strong base weak base This is the only question i need help on and i have no clue what ut is! any

asked by gabby on May 28, 2016
2. chemistry

A 1.0 M acetic acid solution (CH3COOH, pKa = 4.7) is neutralized by dissolving NaOH(s) (a strong base) in the solution. Estimate the pH at the equivalence point of the neutralization process: 4.7 7.0 9.3 Which one of the following

asked by bekah on March 31, 2014
3. chemisty

0.100 M solution of a weak acid, HX, is known to be 15% ionized. The weak acid has a molar mass of 72 g/mol. 1. What is Ka for the weak acid? 2. What is the pH of the buffer prepared by adding 10.0 g of the sodium salt of the acid

asked by Clayton on April 4, 2012
4. Chemistry-Dr Bob help!!

0.100 M solution of a weak acid, HX, is known to be 15% ionized. The weak acid has a molar mass of 72 g/mol. 1. What is Ka for the weak acid? 2. What is the pH of the buffer prepared by adding 10.0 g of the sodium salt of the acid

asked by clayton on April 4, 2012
5. Chemistry

If an equal number of moles of the weak acid HOCN and the strong base KOH are added to water, the resulting solution will be acidic, basic or neutral? There is a complicated answer and a sensible answer. Both arrive at the same

asked by Joel on April 27, 2007
1. Chemistry

In the titration of a weak acid with a strong base, the pH at the equivalence point is affected mostly by a.hydrolysis (reaction with water) of the weak acid b.the dissociation of water molecules c.the presence of excess base

asked by Cheryl on May 26, 2011
2. chemistry (buffers)

How can weak acid nitrous acid HNO2 form a buffer solution with equal concentrations and volumes with weak base NH3? I thought that buffer solutions only occured between weak acids and strong bases or vice versa. The example above

asked by mike on September 1, 2008
3. Chemistry

An unknown monoprotic acid has a pH of 2.87. Is this acid weak or strong if 22.32 mL of 0.112 M NaOH is required to titrate 25.00 mL of the acid? If the acid is weak, calculate its Ka. Answer is Ka = 1.8 x 10^-5, but I don't know

asked by Josh on June 25, 2017
4. Chemistry

Part A: Unknown Acid use 1gram and mix with 120 mL of distilled water Determine the concentration of the acid by titrating with 0.0998 M of NaOH Concentration of NaOH= 0.0998M Volume of NaOH= 3.5 mL # moles of NaOH= Initial

asked by Saira on March 24, 2010
5. chemistry

Weak Acid 1.) The pH of a 0.060M weak monoprotic acid HA is 3.44. Calculate the Ka of the acid. 2.) The pH of 0.100M solution of weak monoprotic acid HA is 2.85. What is the Ka of the acid?

asked by jaycab on January 20, 2011
6. chemistry

Weak Acid 1.) The pH of a 0.060M weak monoprotic acid HA is 3.44. Calculate the Ka of the acid. 2.) The pH of 0.100M solution of weak monoprotic acid HA is 2.85. What is the Ka of the acid?

asked by jaycab on January 20, 2011

More Similar Questions