Results are out! Find what you need...fast. Get quick advice or join the chat
Hey there Sign in to join this conversationNew here? Join for free

could anyone explain to me what im suppose to do?

Announcements Posted on
    • Thread Starter
    • 7 followers
    Offline

    ReputationRep:
    1. solution A contains 6.4 g/ dm cube of a mixture of NaOH and Na2SO4. solution B contain 4.9 g/dm cube H2SO4. only the NaOH in the mixture reacts with the H2SO4 and from titration it was found that:

    25.0cm cube of solution A= 23.95 of H2SO4
    according to the equation:
    H2SO4 (aq) + 2 NaOH (aq) = Na2SO4 (aq) + 2H2O (L)
    find the percentage composition by mass of the mixture (ans. 59.88% NaOH; 40.12% Na2SO4)

    2. solution C contains 11/37 g/dm cube of an acid HX. solution D contains 4.48 g/ dm cube potassium hydroxide solution. on titration it was found that:

    25.0 cm cube of solution D= 22.50 cm cube of solution C

    use these titrations results to find the relative atomic mass of X and hence its identity.the equation for the reaction is:
    KOH (aq) + HC (aq) = KX (aq) + H2O (L)
    • 3 followers
    Offline

    ReputationRep:
    (Original post by Shordaay)
    1. solution A contains 6.4 g/ dm cube of a mixture of NaOH and Na2SO4. solution B contain 4.9 g/dm cube H2SO4. only the NaOH in the mixture reacts with the H2SO4 and from titration it was found that:

    25.0cm cube of solution A= 23.95 of H2SO4
    according to the equation:
    H2SO4 (aq) + 2 NaOH (aq) = Na2SO4 (aq) + 2H2O (L)
    find the percentage composition by mass of the mixture (ans. 59.88% NaOH; 40.12% Na2SO4)

    2. solution C contains 11/37 g/dm cube of an acid HX. solution D contains 4.48 g/ dm cube potassium hydroxide solution. on titration it was found that:

    25.0 cm cube of solution D= 22.50 cm cube of solution C

    use these titrations results to find the relative atomic mass of X and hence its identity.the equation for the reaction is:
    KOH (aq) + HC (aq) = KX (aq) + H2O (L)
    1) You've been given the reaction equation, so first find the moles of sulphuric acid used by using the formula \mathrm{No. \ of \ moles} = \mathrm{concentration \ in \ moldm^{-3} \times \dfrac{volume \ in \ cm^3}{1000}}. It's actually just cancelling units instead of a real formula. You need to convert concentration in gdm-3 to concentration in moldm-3. Using the molar equation, you should be able to find moles of NaOH reacted and so it's concentration in the given volume. Do you get how to do after that?

    2) You should be able to do it now using some of the information I provided in 1. What problem are you facing in it?
    • Thread Starter
    • 7 followers
    Offline

    ReputationRep:
    thank you i understood and did it
    • 0 followers
    Offline

    ReputationRep:
    (Original post by Shordaay)
    thank you i understood and did it
    I have no clue on how to find X in question 2. Can you show me how?
    • 0 followers
    Offline

    ReputationRep:
    (Original post by Golden Boy)
    I have no clue on how to find X in question 2. Can you show me how?
    any change my answer to X = 2.34. But there's no atom with the Relative Atomic Mass of 2.34...

    Are you sure that the solution C has the concentration of 11/37 g/dm^3 ?
    • Thread Starter
    • 7 followers
    Offline

    ReputationRep:
    sorry that must have been a mistake.... 11.37 g dm^3
    • 0 followers
    Offline

    ReputationRep:
    (Original post by Shordaay)
    sorry that must have been a mistake.... 11.37 g dm^3
    I see... thanks for replying.
    • 0 followers
    Offline

    ReputationRep:
    I got X as Iodine.

Reply

Submit reply

Register

Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?
  2. this can't be left blank
    this email is already registered. Forgotten your password?
  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. By joining you agree to our Ts and Cs, privacy policy and site rules

  2. Slide to join now Processing…

Updated: June 9, 2012
New on TSR

Find out what year 11 is like

Going into year 11? Students who did it last year share what to expect.

Article updates
Reputation gems:
You get these gems as you gain rep from other members for making good contributions and giving helpful advice.