Hey there! Sign in to join this conversationNew here? Join for free
x Turn on thread page Beta

Help!: Organic Chem Question watch

Announcements
    • Thread Starter
    Offline

    2
    ReputationRep:
    Please Help!

    Myrcene, C10H16, is a naturally occurring oil present in bay leaves. The structure of myrcene is shown below:

    See attachment

    a) Reaction of a 0.100 mol sample of myrcene with hydrogen at room temperature and pressure (r.t.p.) produced a saturated alkane, A.

    ii) Determine the molecular formula of the saturated alkane, A.

    b)

    Squalene is a naturally occuring oil present in shark-liver oil. A 0.100 mol sample of the squalene reacted with 14.4 dm3 of hydrogen at r.t.p to form a saturated hydrocarbon C30H62.

    i) Calculate how many double bonds there are in each molecule of squalene.
    Attached Images
     
    Offline

    2
    ReputationRep:
    to find the structure of A for each double bond a hydrogen atom is added to each side and the double bond dissappears giving a molecular formula of C10H22 (i think, if i can count)

    for the 2nd part you need to work out number of moles of hydrogen used then devide it by 0.1 then by 2 to find the number of double bonds, as for each 0.1 mole of squalene 0.05 moles of hydrogen is used to satuarte each double bond

    Hope that helps, it sounds clear as mud when i read it back, thats the first chem i did since i left the exam!
    Offline

    14
    ReputationRep:
    (Original post by supreme)
    Please Help!

    Myrcene, C10H16, is a naturally occurring oil present in bay leaves. The structure of myrcene is shown below:

    See attachment

    a) Reaction of a 0.100 mol sample of myrcene with hydrogen at room temperature and pressure (r.t.p.) produced a saturated alkane, A.

    ii) Determine the molecular formula of the saturated alkane, A.
    You should be able to do this, there is only one double bond in the molecule.

    b)

    Squalene is a naturally occuring oil present in shark-liver oil. A 0.100 mol sample of the squalene reacted with 14.4 dm3 of hydrogen at r.t.p to form a saturated hydrocarbon C30H62.

    i) Calculate how many double bonds there are in each molecule of squalene.
    You need to work out the number of moles of hydrogen using PV=nRT where P is pressure, V is volume (14.4 dm3 in this case), n is number of moles, R is the gas constant 8.314 JK-1mol-1, T is temperature in K. If you have the number of moles of hydrogen, divide by the number of moles of squalene and that is the number of double bonds, easy!
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by cobra01977)
    to find the structure of A for each double bond a hydrogen atom is added to each side and the double bond dissappears giving a molecular formula of C10H22 (i think, if i can count)

    for the 2nd part you need to work out number of moles of hydrogen used then devide it by 0.1 then by 2 to find the number of double bonds, as for each 0.1 mole of squalene 0.05 moles of hydrogen is used to satuarte each double bond

    Hope that helps, it sounds clear as mud when i read it back, thats the first chem i did since i left the exam!
    (Original post by ChemistBoy)
    You should be able to do this, there is only one double bond in the molecule.

    You need to work out the number of moles of hydrogen using PV=nRT where P is pressure, V is volume (14.4 dm3 in this case), n is number of moles, R is the gas constant 8.314 JK-1mol-1, T is temperature in K. If you have the number of moles of hydrogen, divide by the number of moles of squalene and that is the number of double bonds, easy!
    Thanks cobra01977 & ChemistBoy
 
 
 
Poll
Do you agree with the proposed ban on plastic straws and cotton buds?

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.