titration of 50ml of 0.25ammonia with 0.5M HCL .
a) find the initial PH value
b) volume of HCL is required to reach the equivalent poinnt
c)the ph at the equivalence point

  1. 👍 0
  2. 👎 0
  3. 👁 45
asked by anne
  1. I'll help you through this but please explain what you know to do and especially what you don't understand about the problem.

    1. 👍 0
    2. 👎 0
  2. i don't understand what i have to do for the calculation. what ive learnes is about acid and base titration . when we add a base to an acid until the equivalence point is reached which is where the moles of acid equals the moles of base ion .from my logicall thinking the initial ph is we use -log(H+)
    and the volume of hcl is 7.

    1. 👍 0
    2. 👎 0
    posted by anne
  3. HCl + NH3 ==> NH4Cl
    b) millimols NH3 = M x mL = approx 12.5 but you need to confirm this an all of the calculations that follow.
    Then millimols HCl needed = 12.5
    M HCl = millimols/mL = 0.5. Solve for mL = mmols/M = 12.5/0.5 = about 25 mL.

    a) You have pure NH3 at the beginning. Make an ICE chart.
    ...........NH3 +H2O ==> NH4^+ + OH^-

    Substitute the E line into the Kb expression and solve for x = (OH^-) and convert that to pH.

    c) You have the salt NH4Cl at the equivalence point and the pH of the solution at that point is determined by the hydrolysis of the salt, and particularly the NH4^+. (NH4Cl) at this point is millimols/mL = 12.5/(50+25) = about 0.17 and you utilize another ICE chart.
    ..........NH4^+ + H2O ==> H3O^+ + NH3

    Substitute the E line into the Ka expression for NH4^+ (which looks like this)
    Ka for NH4^+ = (Kw/Kb for NH3) = (x)(x)/(0.17-x) and solve for x = (H3O^+) and convert to pH.
    Post your work if you get stuck. In the future if you post a question it helps if you tell us exactly what you don't understand about the problem. Often we can show that one step and you're on your way and we don't need to work the entire problem. That makes it easier to help more people.

    1. 👍 0
    2. 👎 0
  4. calculate the pH before the addition of HCL

    1. 👍 0
    2. 👎 0
    posted by ignitius

Respond to this Question

First Name

Your Response

Similar Questions

  1. Chemistry

    Calculate the theoretical pH after 2.50ml and 9.50ml of NaOH has been added in both the titration of HCl and of HC2H3O2.

    asked by anna on May 10, 2011
  2. chemistry

    titration question: How many moles of HCl must have been present in the 25mL of HCl solution in the 2 trials? Given: Trial 1: V of HCl= 25.00mL, V of NaOH used=29.50mL and M of NaOH=0.18M Trial 2: V of HCl=25.00mL, V of NaOH

    asked by robyn on October 28, 2013
  3. chemistry

    Hello. In the class, we did the experiment to calculate the value of Kc for the following reaction: CH3COOH+CH3CH2OH ÌCH3COOCH2CH3+H2O we measured the mass for 5 cm^3 of all 5 compound above: CH3COOH 5.236 g CH3CH2OH 4.021 g

    asked by masaya on November 1, 2008
  4. Chemistry

    Consider the titration of 50mL of 2.0M HNO3 with 1.0M KOH. At eah step, add the following: 0ml, 25ml, 50ml. a) Write a reaction to show the initial reaction b)ICE table c) determine the spectators present after d)Calculate the pH

    asked by Gub on April 6, 2016
  5. Chemistry - Acid Base Titration

    When you complete a acid base titration of NaOH and HCl and how to you find the molarity/concentration of HCl. I used 9 mL of HCl with 50 mL of water. But when solving for concentration, do I use 9 mL or 59 mL (water + HCl)? Also,

    asked by Steve on January 31, 2008
  6. Chemistry II

    Calculate the pH at the equivalence point in the titration of 50ml of 0.20 M methylamine (Kb=4.3*10^-4) with a 0.40 M HCL solution.

    asked by Katie on May 3, 2013
  7. Chemistry

    50mL of 0.1M HCl is mixed with 50mL of 0.1NaOH. delta T = 3^oC. Calculate the enthalpy of neutralization per mole of HCl. assume the specific heat capcity of the solution is 4.18J/g/C and density=1.0g/mL. I tried it but got the

    asked by Vic on August 10, 2007
  8. Chemistry

    If two titrations were completed were completed: 1) the titration of HCl with Na(OH) 2)the titration of HCl with Ba(OH)2 (the concentrations of acid and base for both titrations are the same) How would the titration curves of each

    asked by Niki on March 6, 2012
  9. chemistry

    A titration to standardize a HCl solution was performed by taking 50.0ml hydrochloric acid in a flask with a few drops of phenolphthalein indicator. The burette was filled with 0.15 molar NaOH. The initial reading of the burette

    asked by martha on March 14, 2017
  10. chemistry

    25ml of 0.05M of NaOH and the average volume of HCl is 17.7ml after titration and the concentration of HCl is 0.1028M. Find the [OH] eq (from titration). How do u solve this...

    asked by roshan on March 23, 2011

More Similar Questions