UNIT 2 NATURES CHEMISTRY hydroxyl The shortened structural

UNIT 2 NATURE’S CHEMISTRY

hydroxyl

The shortened structural formula for an organic compound is CH 3 CH(CH 3)CH(OH)C(CH 3)3 Which of the following is another way of representing this structure?

The first four members of the amine homologous series are: What is the general formula for this homologous series? A Cn Hn+4 N B Cn H 2 n+3 N C Cn H 3 n+2 N D Cn H 4 n+1 N CH 5 N C 2 H 7 N C 3 H 9 N C 4 H 11 N

C 4 H 6 C 5 H 8 C 6 H 10

ISOMERS What is meant by the term isomer? SAME MOLECULAR FORMULA BUT DIFFERENT STRUCTURAL FORMULAE

ADDITION

OH H H OH

Both compounds are unsaturated. Describe the chemical test for unsaturation. BROMINE DECOLOURISED

Name the functional group CARBOXYL HYDROXYL

C 3 H 8 S H 8 C 3 S SH 8 C 3 SAME MOLECULAR FORMULA BUT DIFFERENT STRUCTURAL FORMULAE

EXOTHERMIC Eh = cmΔT 4· 18 x 0· 1 x 8 = 3· 344 k. J

6· 4 g of methanol (CH 3 OH) raises the temperature of 100 cm 3 of water from 21 °C to 40 °C Calculate the energy, in k. J, absorbed by the water. Eh = cmΔT 4· 18 x 0· 1 x 19 = 7· 942 k. J

Eh = cmΔT 4· 18 x 0· 2 x 40 = 33· 44

In one experiment the burning of ethanol resulted in the temperature of 400 cm 3 of water rising from 14 o. C to 30 o. C. Calculate the energy absorbed by the water. Eh = cmΔT 4· 18 x 0· 4 x 16 = 26· 75 k. J

In one experiment the burning of methanol resulted in the temperature of 100 cm 3 of water rising from 19 o. C to 59 o. C. Calculate the energy released. Eh = cmΔT 4· 18 x 0· 1 x 40 = 16· 72 k. J

Calculate the mass of carbon dioxide produced when 4 g of methane burns completely. CH 4 + 2 O 2 CO 2 + 2 H 2 O 1 mole 12 + (1 x 4) 12 + (16 x 2) 16 g 4 g 4/16 = 0· 25 44 x 0· 25 = g 11

Calculate the mass of carbon dioxide produced when 4 g of methane burns completely. CH 4 + 2 O 2 CO 2 + 2 H 2 O 1 mole 12 + (1 x 4) 12 + (16 x 2) 16 g 1 g 4 g 44/16 = 2· 75 g 4 x 2· 75 g = 11 g