chemistry
posted by kelly
10.0mL of solution containing 20.0 mL of 1.0 M NaX (unknown base) and 10.0 mL of 1.0 M HX (unknown acid) was diluted with 50.0 ml water. The pH is 4.92. What is the concentration of HX after dilution and X after dilution? What is the equilibrium concentration of HX, X, and H3O+?

DrBob222
Original solution:
moles NaX = M x L = 1.0 x 0.020 0.02 mol
moles HX = M x L = 1.0 x 0.01 = 0.01 mol
total volume = 30 mL = 0.030 L.
How much did we remove with 10 mL?
0.02 x (10/30) = 0.00667 moles NaX
0.01 x (10/30) = 0.00333 moles HX
Then took that many moles and diluted the whole thing to 50 mL (0.050 L).
Concn final solution:
M = moles/L = 0.00667/0.05 = ?? NaX
and 0.00333/0.05 = ?? HX.
This will give you NaX and HX in the final diluted solution.
That's the confusing part. The rest of the problem is easier. The equilibrium concns is done as follows:
pH is given. Convert that to H^+. That is the equilibrium H^+. X^ will be sum of H^+ + original X.
Respond to this Question
Similar Questions

Chemistry, Buffers, pH
Hi could someone please help me in the next 5 minutes with this question: Given this data: mass of unknown acid 1.4671g Volume of NaOH used in titration 18.47mL Concentration of the NaOH used 0.2403M pH of the original acid solution … 
Chemistry
Suppose 50.0 mL of an aqueous solution containing an unknown monoprotic weak acid is titrated with 0.250 M KOH. The titration requires 31.52 mL of the potassium hydroxide solution to reach the equivalence point. What is the concentration … 
Chemistry, pH, Buffers
Please help!! Given this data: mass of unknown acid 1.4671g Volume of NaOH used in titration 18.47mL Concentration of the NaOH used 0.2403M pH of the original acid solution 2.16 pH of the final acid solution 3.49 Show me how do I calculate … 
College Chemistry
You weigh a sample of a monoprotic unknown acid and dissolve it in 50.00 mL of distilled water. Exactly half of this solution is titrated with Sodium Hydroxide to the phenolphthalein end point. The pH of the other half of the original … 
Chemistry
Consider a solution containing 4.35 mM of an analyte, X, and 1.09 mM of a standard, S. Upon chromatographic separation of the solution peak areas for X and S are 3251 and 10075, respectively. Determine the response factor for X relative … 
Chemistry
A 5.00mL sample of a sulfuric acid solution of unknown concentration is titrated with a 0.1401 M Sodium Hydroxide solution. A volume of 5.99 mL of the base was required to reach the endpoint. What is the concentration of the unknown … 
chemistry
You weigh a sample of a monoprotic unknown acid and dissolve it in 50.00 mL of distilled water. Exactly half of this solution is titrated with Sodium Hydroxide to the phenolphthalein end point. The pH of the other half of the original … 
chemistry
30 ml of sample of unknown strong base is neutralized after the addition of 12 ml of a 0.150 M HNO3 solution if the unknown base concentration 0.0300 M give the possible identities for the unknown base 
chemistry
A 30 ml sample of unknown strong base is neutralized after the addition of 12 ml of a 0.150 M HNO3 solution if the unknown base concentration is 0.0300 M give some possible identities for the unknown base 
Chemistry
Please help, I can't do this and its stressing me out ?