Turn on thread page Beta
    • Thread Starter
    Offline

    9
    ReputationRep:
    Hey! Can anyone help me with the following question ?

    in an experiment, an 8.14 g sample of lead reacted completely with a 2.00 mol dm^-3 solution of nitric acid.
    calculate the volume in dm^3, of nitric acid required for the complete reaction.

    equation - 3Pb(s) +8HNO3(aq) -----> 3Pb(NO3)2(aq) + 2NO(g) + 4H2O(l)

    all help and hints are appreciated!!!
    Offline

    13
    ReputationRep:
    Is it 0.05?
    • Thread Starter
    Offline

    9
    ReputationRep:
    (Original post by AnALevelStudent)
    Is it 0.05?
    i dont know i was getting so confused and i couldnt even get a method that looked right.....
    what was your method???
    Offline

    19
    ReputationRep:
    Moles (n) = Mass/Mr, in this case, considering Lead, with a Mr of 207.2, n = 8.14/207.2, which is roughly 0.039 moles

    In this reaction, it is a 3:8 ratio, thus, to find the amount of moles that Nitric Acid reacted with, you divide 0.039 by 3, and multiply by 8, which gives you 0.104.

    You should know that Concentration is equal to n/v (where n is moles and v is volume, in dm^3)
    rearranging this, we should get cv = n, thus v, the variable we're looking for, is equal to n/c
    Substituting our 2 known values of n and c, 0.104 and 2.00 respectively, we get
    0.104/2 = 0.052 (i rounded this up but around this point) dm^3.
    Offline

    13
    ReputationRep:
    Name:  IMG_8302.jpg
Views: 20
Size:  480.3 KB
    (Original post by tats bentata)
    i dont know i was getting so confused and i couldnt even get a method that looked right.....
    what was your method???
    Hope this makes sense
    Offline

    13
    ReputationRep:
    Yeah I meant 0.052 idk why I put 0.055
    • Thread Starter
    Offline

    9
    ReputationRep:
    thank you both so much!!!
    i think i started correctly but then forgot about the ratio....
    very much appreciated!!!
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: October 26, 2017
The home of Results and Clearing

1,184

people online now

1,567,000

students helped last year

University open days

  1. SAE Institute
    Animation, Audio, Film, Games, Music, Business, Web Further education
    Thu, 16 Aug '18
  2. Bournemouth University
    Clearing Open Day Undergraduate
    Fri, 17 Aug '18
  3. University of Bolton
    Undergraduate Open Day Undergraduate
    Fri, 17 Aug '18
Poll
Do you want your parents to be with you when you collect your A-level results?

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

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