Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    14
    ReputationRep:
    Hi,
    Say you were adding a strong base to a strong acid I know the PH curve will start ataround 2 and rise slowly but stay low as long as long as there is still some H+ present from the acid. Just before the vertical stretch however the PH curve starts to increase more quickly and could not think of why??
    I know the acid is in less excess at this point but surely the concentration of H+ will be decreasing at the same rate. Or is it linked to the fact that while the rate of decrease of H+ ions will be the same, the percentage decrease in the concentration will be more thus having a greater effect on PH.

    Also does an indicator such as methyl orange have a red colour all the way to its end point, change and then retain that colour no matter how high the ph goes or is the indicator "activated within a certain PH range.
    Thanks
    Offline

    17
    ReputationRep:
    The pH scale is logarithmic, to go from pH 1-2 need ten times more alkali than to go from pH 2-3 etc.

    Indicators as weak acids and can be expressed as follows: HI <-> H+ + I-

    HI is one colour, I- is another colour.
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    What newspaper do you read/prefer?
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

    Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

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