Docsity
Docsity

Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity


Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan


Guidelines and tips
Guidelines and tips

S B C9 C O a F, Slides of Chemistry

BBC bitesize – hydrocarbons and alkanes ... The first four alkanes (methane, ethane, propane and butane) are gases at room ... BBC bitesize – crude oil.

Typology: Slides

2021/2022

Uploaded on 09/12/2022

leyllin
leyllin 🇬🇧

4.3

(15)

242 documents

1 / 85

Toggle sidebar

This page cannot be seen from the preview

Don't miss anything!

bg1
!
S B
C9 C O a F
pf3
pf4
pf5
pf8
pf9
pfa
pfd
pfe
pff
pf12
pf13
pf14
pf15
pf16
pf17
pf18
pf19
pf1a
pf1b
pf1c
pf1d
pf1e
pf1f
pf20
pf21
pf22
pf23
pf24
pf25
pf26
pf27
pf28
pf29
pf2a
pf2b
pf2c
pf2d
pf2e
pf2f
pf30
pf31
pf32
pf33
pf34
pf35
pf36
pf37
pf38
pf39
pf3a
pf3b
pf3c
pf3d
pf3e
pf3f
pf40
pf41
pf42
pf43
pf44
pf45
pf46
pf47
pf48
pf49
pf4a
pf4b
pf4c
pf4d
pf4e
pf4f
pf50
pf51
pf52
pf53
pf54
pf55

Partial preview of the text

Download S B C9 C O a F and more Slides Chemistry in PDF only on Docsity!

SWXGHQW BRRNOHW

C9 CUXGH OLO aQG FXHOV

%LJ,GHD6WUXFWXUH'HWHUPLQHV3URSHUWLHV :KDWGRHVWKLVPHDQ" <RXZLOONQRZIURPSUHYLRXVXQLWVWKDWWKHUHDUHPDQ\GLIIHUHQWNLQGVRIPROHFXOHVDQGWKHVHFDQDOOORRNYHU
GLIIHUHQW$PROHFXOHRIZDWHUORRNVGLIIHUHQWWRDPROHFXOHRIR[\JHQ7KHGLIIHUHQW VWUXFWXUHV RIPROHFXOHVUHVXOW LQWKHPKDYLQJPDQ\GLIIHUHQW SURSHUWLHV b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
ILQGRUJDQLFFRPSRXQGVLQOLYLQJRURQFHOLYLQJPDWHULDOVIURPSODQWVDQGDQLPDOV7KHVHVRXUFHVLQFOXGHIRVVLO IXHOVZKLFKLVWKHPDLQUDZPDWHULDOIRUWKHRLO DQGJDVLQGXVWU\&KHPLVWVDUHDEOHWRWDNHRUJDQLFPROHFXOHVDQG PRGLI\WKHPLQPDQ\ZD\VWRPDNHQHZDQGXVHIXOPDWHULDOVVXFKDVSRO\PHUVSKDUPDFHXWLFDOVSHUIXPHV DQGbIODYRXULQJVG\HVDQGGHWHUJHQWV

)ROORZWKHOLQNVEHORZWRUHYLHZVRPHRIWKHNH\NQRZOHGJHWKDWZLOOKHOS\RXLQWKLVXQLW

)LUVWO\\RXVKRXOGNQRZWKHGLIIHUHQFHEHWZHHQDWRPVHOHPHQWVDQGFRPSRXQGV<RX OOILQGPRUHLQIRUPDWLRQRQWKHVHKHUH KWWSVZZZEEFFRXNELWHVL]HJXLGHV]JKTWUHYLVLRQ

,W VLPSRUWDQWWKDW\RXFDQUHPHPEHUDOODERXWDWRPLFVWUXFWXUH WKHVWUXFWXUHRIDWRPV 7KLVLVVXPPDULVHGKHUHIRU\RXLQ FDVH\RXGRQ WUHPHPEHUKWWSVZZZEEFFRXNELWHVL]HJXLGHV]VJQEUHYLVLRQ

<RXVKRXOGNQRZWKDWWKHUHDUHGLIIHUHQWW\SHVRIERQGLQJDQGZKDWKDSSHQVLQHDFKRIWKHVH<RX OOILQGPRUHLQIRUPDWLRQ RQWKHVHKHUHKWWSVZZZEEFFRXNELWHVL]HDUWLFOHV]\N

$QRWKHUXVHIXOWRSLF\RX YHOHDUQHGDERXWLVJLDQWFRYDOHQWVWUXFWXUHV7KLVLVDQRWKHUSODFHZKHUH\RXZHUHDEOHWROLQN VWUXFWXUHWRSURSHUWLHV UHPHPEHUGLDPRQGDQGJUDSKLWH" 5HPLQG\RXUVHOIRIWKHVHKHUH KWWSVZZZEEFFRXNELWHVL]HJXLGHV]WZVUGUHYLVLRQ

:KDWZLOO,EH

OHDUQLQJDERXW"

7KHPRVWLPSRUWDQWSUHYLRXVXQLWVWRKHOSZLWKWKLVOHDUQLQJDUH&&&&& %RRNOHWVDUHDYDLODEOHIRUHDFKRIWKHVHXQLWV

:KDWVKRXOG,DOUHDG\

NQRZ"

3DQG4UHDFWWRIRUPDQLRQLFFRPSRXQG:KDWLVWKHIRUPXODRIWKLVFRPSRXQG" $34 %3 &

(QGRI8QLW3UH7HVW7XUQRYHUWRVHHWKHDQVZHUV*LYH\RXUVHOIDPDUNRXWRI

:K\GRHVQ WJUDSKLWHPHOWDWGHJUHHV&HOVLXV" $,WKDVVWURQJFRYDOHQWERQGV %,WKDVDJLDQWLRQLFODWWLFH &,WLVPDGHRIFDUERQDWRPV

:KLFKLVWKHFRUUHFWGRWDQGFURVVGLDJUDP"

7KHHOHFWURQLFVWUXFWXUHVRIDWRPV3DQG4DUHVKRZQ

:KLFKRIWKHIROORZLQJFRXOGUHSUHVHQWDFKHPLFDOUHDFWLRQ" $

%

&

'

3UH7HVW$QVZHUV

4XHVWLRQ $QVZHU :KDWWRGRQH[W IL[LWWDVN

 &

,I\RXDQVZHUHG$WKLVVKRZVWKDW\RXKDYHFRUUHFWO\VWDWHGWKHFKDUJHRIWKHSURWRQEXWIRUWKH ORFDWLRQ\RXSLFNHG LQWKHPLGGOH ZKLFKLVLQFRUUHFW $QVZHULQJ%VKRZVWKDW\RXKDYHFRUUHFWO\LGHQWLILHGWKHORFDWLRQRIWKHSURWRQLQWKHQXFOHXVEXW \RXKDYHPL[HGXSWKHFKDUJH SRVLWLYH ZLWKLWVPDVVZKLFKLV ,I\RXDQVZHUHG$RU%\RXVKRXOGUHYLVHWKHVWUXFWXUHRIWKHDWRPDQGSUDFWLVHGUDZLQJ\RXURZQ ODEHOOLQJHDFKVXEDWRPLFSDUWLFOHZLWKLWVUHODWLYHFKDUJHDQGORFDWLRQ

 &

,I\RXDQVZHUHG$RU%\RXQHHGIXUWKHUSUDFWLFHGUDZLQJHOHFWURQLFFRQILJXUDWLRQVRIGLIIHUHQW HOHPHQWV'UDZDWRPVIURPHDFKJURXSRIWKHSHULRGLFWDEOHVRWKDW\RXFDQVHHWKDWDOWKRXJKWKH
KDYHWKHVDPHQXPEHURIHOHFWURQVLQWKHLURXWHUVKHOOWKH\GRQRWKDYHFRPSOHWHO\WKHVDPH FRQILJXUDWLRQEHFDXVHWKH\KDYHGLIIHUHQWDWRPLFQXPEHUV6HHKHUHIRUPRUHKHOSRQGUDZLQJ HOHFWURQLFFRQILJXUDWLRQKWWSVZZZEEFFRXNELWHVL]HJXLGHV]JNUHYLVLRQ

 $

,I\RXDQVZHUHG$RU%\RXQHHGIXUWKHUSUDFWLFHGUDZLQJHOHFWURQLFFRQILJXUDWLRQVRIGLIIHUHQW HOHPHQWV'UDZDWRPVIURPHDFKJURXSRIWKHSHULRGLFWDEOHVRWKDW\RXFDQVHHWKDWDOWKRXJKWKH
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

 %

 &

,I\RXJHWWKLVZURQJWKHQ\RXQHHGWRILQGRXWWKHGLIIHUHQFHEHWZHHQFKHPLFDOUHDFWLRQVDQG SK\VLFDOFKDQJHV0DNHDWDEOHWRFRPSDUHFKHPLFDOUHDFWLRQVDQGSK\VLFDOFKDQJHVOLVWLQJDWOHDVW GLIIHUHQFHVEHWZHHQWKHP

 %

,I\RXFKRVH$WKHQ\RXKDYHLQFRUUHFWO\VXEWUDFWHGWKHPDVVRI0JIURP27KLVPHDQV\RXVKRXOG UHYLVHFRQVHUYDWLRQRIPDVV 7KHWRWDOPDVVRIUHDFWDQWVVKRXOGHTXDOWKHWRWDOPDVVRIWKHSURGXFWV  ,I\RXFKRVH$RU&UHDGWKURXJKWKHLQIRUPDWLRQKHUHDQGWU\WKHTXL]DWWKHHQG KWWSVZZZEEFFRXNELWHVL]HJXLGHV]EI[IUUHYLVLRQ

 $

,I\RXFKRVH%WKLVLVLQFRUUHFWEHFDXVHJUDSKLWHKDVFRYDOHQWERQGVEHWZHHQ&DWRPV7KLVDQVZHU VKRZVDPLVWDNHDERXWWKHW\SHRIERQGLQJLQJUDSKLWH7RLPSURYH\RXUXQGHUVWDQGLQJFRPSDUH DQGFRQWUDVWLRQLFDQGFRYDOHQWERQGVXVLQJDWDEOHRUPLQGPDS,I\RXFKRVH&LWLVWUXHWKDW JUDSKLWHLVPDGHRIFDUERQDWRPVEXWWKLVGRHVQ WKDYHDQ\HIIHFWRQLW VPHOWLQJSRLQW<RXVKRXOG ZULWHGHILQLWLRQVIRUPHOWLQJDQGERLOLQJSRLQWDQGWKHQH[SODLQZK\JLDQWFRYDOHQWVWUXFWXUHVKDYH DKLJKHUPHOWLQJDQGERLOLQJSRLQWWKDQVPDOOFRYDOHQWPROHFXOHV







$

%

'

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

,Q&DWDO\WLF&UDFNLQJDKRWDONDQHLVSDVVHGRYHUDKRWFDWDO\VWDQGFUDFNLQJSURGXFHVWKHJDVHRXVSURGXFW7KLVPHWKRGLV XVHGLQDODERUDWRU\ ,Q6WHDP&UDFNLQJWKHDONDQHLVPL[HGZLWKVWHDPDQGKHDWHGWRDYHU\KLJKWHPSHUDWXUH7KLVPHWKRGLVXVHGLQLQGXVWU\

7KHIUDFWLRQVFDQEHSURFHVVHGWRbSURGXFHIXHOVDQGIHHGVWRFNb FKHPLFDOV IRUWKHSHWURFKHPLFDOLQGXVWU\

0DQ\RIWKHIXHOVRQZKLFKZHGHSHQGIRURXUPRGHUQOLIHVW\OHVXFKDVbSHWUROGLHVHORLONHURVHQHKHDY\IXHORLODQGOLTXHILHG SHWUROHXPJDVHVDUHSURGXFHGIURPFUXGHRLO 0DQ\XVHIXOPDWHULDOVRQZKLFKPRGHUQOLIHGHSHQGVDUHSURGXFHGE\WKHSHWURFKHPLFDOLQGXVWU\VXFKDVVROYHQWVOXEULFDQWV SRO\PHUVGHWHUJHQWVbbbb

3URSHUWLHVRIK\GURFDUERQV bb

6RPHSURSHUWLHVRIK\GURFDUERQVGHSHQGRQWKHVL]HRIWKHLUPROHFXOHVLQFOXGLQJbERLOLQJSRLQWYLVFRVLW\DQGIODPPDELOLW\ 7KHVHSURSHUWLHVLQIOXHQFHKRZK\GURFDUERQVDUHXVHGDVIXHOVbbb

9LVFRVLW\ KRZHDVLO\DVXEVWDQFHIORZVHJKRQH\LVPRUHYLVFRVHWKDQZDWHUEHFDXVHLWIORZVOHVVHDVLO\bb )ODPPDELOLW\ KRZHDVLO\DVXEVWDQFHbEXUQVbb

%RLOLQJSRLQW6KRUWHUK\GURFDUERQVKDYHIHZHULQWHUPROHFXODUIRUFHVVRKDYHDORZHUERLOLQJSRLQW/RQJHUK\GURFDUERQVKDYH PRUHLQWHUPROHFXODUIRUFHVVRKDYHDKLJKHUERLOLQJSRLQWbb

9LVFRVLW\6KRUWHUK\GURFDUERQVKDYHIHZHULQWHUPROHFXODUIRUFHVVRDUHOHVVYLVFRVH/RQJHUK\GURFDUERQVKDYHPRUH LQWHUPROHFXODUIRUFHVVRDUHPRUHYLVFRVHbb

)ODPPDELOLW\6KRUWHUK\GURFDUERQVKDYHIHZHULQWHUPROHFXODUIRUFHVVRDUHPRUHIODPPDEOH/RQJHUK\GURFDUERQVKDYHPRUH LQWHUPROHFXODUIRUFHVVRDUHOHVVIODPPDEOHbb

&RPEXVWLRQRIK\GURFDUERQV b 7KHFRPEXVWLRQRIK\GURFDUERQIXHOVUHOHDVHVHQHUJ\'XULQJFRPEXVWLRQWKHFDUERQDQGK\GURJHQLQWKHIXHOVDUHbR[LGLVHGbbb

&RPSOHWHFRPEXVWLRQbb+\GURFDUERQ2[\JHQb&DUERQ'LR[LGH:DWHUb

(J0HWKDQH2[\JHQb&DUERQ'LR[LGH:DWHUbbbbbbbbbbbb&+bbb2bbbbb&2bb+

&UDFNLQJDQG$ONHQHVb b +\GURFDUERQVFDQEHEURNHQGRZQ FUDFNHG WRSURGXFHVPDOOHUPRUHXVHIXOPROHFXOHV &UDFNLQJFDQEHGRQHE\YDULRXVPHWKRGVLQFOXGLQJbFDWDO\WLFFUDFNLQJbDQGbVWHDPFUDFNLQJbbb 'HILQLWLRQRIFUDFNLQJ,QFUDFNLQJDORQJDONDQHLVEURNHQGRZQLQWRDVKRUWHUDONDQHDQGDQDONHQH

,WLVDQH[DPSOHRIDWKHUPDOGHFRPSRVLWLRQUHDFWLRQEHFDXVHKHDWLVDGGHGDQGFDXVHVWKHUHDFWDQWWREUHDNGRZQWRIRUP SURGXFWV





+RZGRZHWHVWIRUDONHQHV" b7KHWHVWIRUDONHQHVLVWRUHDFWZLWKbEURPLQHZDWHUb֝ WKHEURPLQHZDWHUWXUQVIURPbEURZQ WRbFRORXUOHVVbbb :K\LVFUDFNLQJXVHIXO" b7KHSURGXFWVRIFUDFNLQJLQFOXGHVKRUWHUDONDQHVDQGDQRWKHUW\SHRIK\GURFDUERQFDOOHGbDONHQHV 7KHUHLVDKLJKGHPDQGIRUIXHOVZLWKVPDOOPROHFXOHVDQGVRVRPHRIWKHSURGXFWVRIFUDFNLQJDUHXVHIXODVIXHOV$ONHQHVDUH XVHGWRSURGXFHbSRO\PHUVbDQGDVVWDUWLQJPDWHULDOVbIRUWKHSURGXFWLRQRIbPDQ\RWKHUFKHPLFDOV 

Lesson 1

Hydrocarbons and alkanes

What are hydrocarbons and alkanes?

Hydrocarbons are compounds that are made of carbon and hydrogen atoms only ; these atoms are covalently bonded together. Many hydrocarbons are used as fuels as they are a chemical store of energy and they burn in a controlled way.

Alkanes are an example of a homologous series that have similar chemical properties and have the same general formula of C n H 2 n +2 , where n is the number of carbon atoms. This means that if there are 4 carbon atoms, there will be (2x 4 )+2 hydrogen atoms giving a formula of C 4 H 10. If there are 6 carbon atoms, there will be (2x 6 )+2 hydrogen atoms giving a formula of C 6 H 14.

Alkanes contain the functional group of a carbon – carbon single bond.

Examples of alkanes

All of the alkanes have the suffix ‘-ane’

1. Methane (top tip! Remember the prefix ‘Me-’ as there is only one of you!)

Methane is the first alkane within the homologous series and has the formula CH 4. This formula shows there is one carbon atom and 4 hydrogen atoms.

**2. Ethane – C 2 H 6

  1. Propane – C 3 H 8
  2. Butane – C 4 H 10**

BBC bitesize – hydrocarbons and alkanes

Properties of alkanes

The first four alkanes (methane, ethane, propane and butane) are gases at room temperature.

They have very low boiling points because there are weak intermolecular forces of attraction between the molecules. These forces of attraction do not require much energy to be overcome for melting and boiling to happen.

As the number of carbon atoms in a hydrocarbon molecule increases, the length of the carbon chain increases, so does the boiling point of the alkane. This is because there is more surface area of the molecule for the intermolecular forces to form.

Example: State of Pentane and methane at room temperature

Methane is a much smaller molecule than pentane, so there is less surface area for intermolecular forces of attraction in methane. This means that less energy is needed to move molecules of methane apart compared to pentane. Therefore, methane is a gas at room temperature and pentane is a liquid.

You will learn more about the properties of different length hydrocarbons in the next lesson.

Lesson 1 Glossary

Keyword Definition

  1. Alkane A homologous series of saturated (contain carbon-carbon single bond) hydrocarbons
  2. Boiling point The temperature at which a liquid boils and turns to vapour.
  3. Covalent bond A shared pair of electrons between non- metal atoms.
  4. Functional group The group of atoms and bonds which characterises a group of organic chemicals.
  5. Homologous series A family of compounds that will have the same general formula and similar properties but differ by the number of carbon atoms. Homologous series:
    • differ by CH 2 in molecular formulae from neighbouring compounds
    • show a gradual variation in physical properties, such as their boiling points
    • have similar chemical properties
  6. Hydrocarbon A compound made up of carbon and hydrogen atoms only.
  7. Intermolecular forces Interactions between molecules that determine a compounds melting/boiling point.

Exam questions

Q1.

This question is about hydrocarbons.

(a) The names and formulae of three hydrocarbons in the same homologous series are:

Ethane C 2 H 6

Propane C 3 H 8

Butane C 4 H 10

The next member in the series is pentane.

What is the formula of pentane? (1)

(b) Which homologous series contains ethane, propane and butane? (1)

Tick one box.

Alcohols

Alkanes

Alkenes

Carboxylic acids

(c) Octane (C 8 H 18 ) is a hydrocarbon found in petrol.

Explain why octane is a hydrocarbon. (2)

Q2.

This question is about compounds produced from crude oil.

The table below shows four of these compounds.

Compound Melting point in °C Boiling point in °C

methane (CH 4 ) −183 −

ethene (C 2 H 4 ) −169 −

decane (C 10 H 22 ) −30 +

icosane (C 20 H 42 ) +37 +

(a) Tick ( ) two correct statements about the four compounds. (2)

Statement Tick ( )

Methane has the lowest melting point and icosane has the highest boiling point.

Ethene and methane are alkanes.

Methane and decane are gases at room temperature (20°C).

Decane and icosane are liquid at 100°C.

Q4.

The table shows some information about alkanes.

Name Formula Relative formula mass Boiling point in °C

methane CH 4 16 –

ethane C 2 H 6 30 –

propane 44 –

butane C 4 H 10 58

pentane C 5 H 12 72 36

hexane C 6 H 14 86 68

(a) Give the formula of propane. (1)

(b) What happens to the boiling points of the alkanes as the relative formula mass increases? (1)

(c) Draw a graph. Plot the points and draw a best fit line. (3)

(d) What is the boiling point of butane? (1)

(e) Show clearly on the graph how you found the boiling point of butane. (1)

(f) Circle which of the following is not an alkane. (1)

C 71116 C 9 H 18 C 11 H 24 C 24 H 50

1. What is the correct formula of butane? a. C 4 b. C 4 H 8 c. C 4 H 10 2. Which compound could be described as a hydrocarbon and an alkane? a.

b.

c.

3. What does this line represent? (see purple arrow)

a. An ionic bond between carbon and hydrogen atoms b. A single covalent bond between carbon and hydrogen atoms c. A double covalent bond between carbon and hydrogen atoms

If you answered A , you are mistakenly thinking that butane only contains carbon atoms. Butane is a hydrocarbon and contains carbon and hydrogen atoms only. There are 4 carbon atoms, you are correct in thinking this but there are also 10 hydrogen atoms. To ‘fix it’, write the formula of ethane, pentane and heptane.

If you answered B , you have used the general formula CnH2n+2 incorrectly and have doubled the number of carbon atoms but have not added two additional carbon atoms after doubling. To ‘fix it’, if pentane has 5 carbon atoms use the general formula CnH2n+2 to calculate the number of hydrogen atoms.

If you answered C , you think that the formula of butane is C 4 H 10. This is correct! Well done for correctly using the general formula CnH2n+2 to determine the formula. To stretch your knowledge further, explain why the formula of dodecane is C 12 H 26.