Turn on thread page Beta

Can you explain the answers to these questions please? watch

    • Thread Starter
    Offline

    1
    ReputationRep:
    1.
    Most modern cars are fitted with airbags. These work by decomposing sodium azide to liberate nitrogen gas, which inflates the bag.
    2NaN3 3N2 + 2Na

    A typical driver’s airbag contains 50 g of sodium azide.
    Calculate the volume of nitrogen this will produce at room temperature.

    A 9.2 dm3

    B 13.9 dm3

    C 27.7 dm3

    D 72.0 dm3

    2.What is the number of molecules in 500 cm3
    of oxygen under room conditions?
    A 1.25 x 1022

    B 1.34 x 1022

    C 3.0 x 1022

    D 3.0 x 1026

    ( 22 = Power of 10)



    Thanks =D
    Offline

    11
    ReputationRep:
    For the first one, calculate the number of moles of sodium azide using its molecular weight. From the equation, you can see that you produce one and a half moles of nitrogen gas for each mole of NaN3. Then simply remember that one mole of an ideal gas takes up 22.4 litres and bob's your uncle!
    Offline

    1
    ReputationRep:
    For the first one:Number of mole NaN3 =50/{23 (14×3)} =0.7692 molRatio is 2:3Therefore Number of mol N2 = 3/2 × 0.7692 = 1.1583 molVolume of N2 = 1.1583 ×24 = 27.7 dm^3 Answer is C
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: March 28, 2018

University open days

  • University of Warwick
    Undergraduate Open Days Undergraduate
    Sat, 20 Oct '18
  • University of Sheffield
    Undergraduate Open Days Undergraduate
    Sat, 20 Oct '18
  • Edge Hill University
    Faculty of Health and Social Care Undergraduate
    Sat, 20 Oct '18
Poll
Who is most responsible for your success at university

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.