1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Chem Lab: Acids and Bases

  1. Feb 28, 2006 #1
    In my chmeistry lab i use a pipet 5.0 ml of HCl and add it to a beaker. To this beaker I also added 5.0 ml NaOH. I stir the mixture and when a red litmus it turn to blue and when i put a blue litmus it stay blue. So that means its a base, but since its a mixture of an acid and a base shouldn't it be neutral? Did I do something wrong or is it correct?
     
  2. jcsd
  3. Mar 1, 2006 #2

    Hootenanny

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    If your pH test are showing an alkaline solution, then you have either added too much Sodium Hydroxide or the Sodium Hydroxide is more concentrated than the Hydrochloric Acid. In my experience you never get exactly a neutral solution, you tend to go a bit too far.
     
  4. Mar 1, 2006 #3

    Borek

    User Avatar

    Staff: Mentor

    Assuming you measured volumes with 1% accuracy (not bad) your solution may contain up to 2% excess of one of the reagents. Assuming 0.1M solutions your pH can be anywhere between 3.00 and 11.00 - looks like you have overshot :wink:
     
  5. Mar 2, 2006 #4
    well my lab teacher provided the Hcl and NaOH so we don't know how concentrated it is. She only told us to use 5 ml of each and when I put the red litmus it turn blue which means its base. So from my understanding Naoh is more concentrated then HCl since they both had the same amout of ml. Am I Correct?
     
  6. Mar 2, 2006 #5

    Hootenanny

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Yes, assuming of course that you added the same amount, the pipette will have a standard error associated with the volume.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Chem Lab: Acids and Bases
  1. Chem. Lab (Replies: 2)

  2. Acids and bases (Replies: 7)

Loading...