TMA3/CHM192

My TMA Home TMA Results My Pending TMA Quick Help TMA Quiz Questions TMA: TMA3/CHM192 Matric Number:  score=10.00 september 2016 CHM192 - Introductory Chemistry Practical II Miss Abdul Modupe (mabdul@noun.edu.ng ) 1 Which of the following is a recrystallization solvent? Diethyl ether Water Ethanol All of the above 2 Which statement explains why the element "Carbon" forms so many compounds? Carbon atoms combine readily with Oxygen Carbon atoms have very high electronegativity Carbon atoms readily form ionic bonds with other carbon atoms Carbon atoms readily form covalent bonds with other carbon atoms 3 Dehydration of an alcohol leads to the formation of an ____________. Alkane Alkene Alkyne Aldehyde 4 Which statement about benzene is correct? Benzene is an isomer of cyclohexane The ratio of carbon to hydrogen atoms in benzene is the same as in ethyne Benzene reacts with bromine solution as if it is saturated Benzene undergoes addition reaction more readily than hexene. 5 Which of the following condensed formulae is accurate for 2,2-dimethylbutane? CH3C(CH3)2CH2CH3$$C{H}_{3}C(C{H}_3{)}_{2}C{H}_{2}C{H}_3$$ CH3C(CH3)CH2CH3$$C{H}_{3}C(C{H}_3)C{H}_{2}C{H}_3$$ CH3(CH3)2CH2CH3$$C{H}_3(C{H}_3{)}_{2}C{H}_{2}C{H}_3$$ CH3C(CH3)2CH2CH3$$C{H}_{3}C(C{H}_3{)}_{2}C{H}_{2}C{H}_3$$ 6 Which of these compounds is a saturated hydrocarbon? Ethene Ethane Ethyne Ethanol 7 In a molecule of CH4$$C{H}_4$$ , the hydrogen atoms are spatially oriented towards the center of a regular ___________ Tetrahedron Pyramid Rectangle Square 8 In which pair of hydrocarbons does each compound contain only one double bond per molecule? C2H2$$C_2{H}_2$$ and C2H6$$C_2{H}_6$$ C2H2$$C_2{H}_2$$ and C3H6$$C_3{H}_6$$ C4H8$$C_4{H}_8$$ and C2H4$$C_2{H}_4$$ C6H6$$C_6{H}_6$$ and C7H8$$C_7{H}_8$$ 9 Which element is present in all organic compounds? Nitrogen Oxygen Carbon Phosphorus 10 Which of these compounds is an organic acid? CH3OCH3$$C{H}_{3}OC{H}_3$$ CH3OH$$C{H}_{3}OH$$ CH3COOH$$C{H}_{3}COOH$$ CH3COOCH3$$C{H}_{3}COOC{H}_3$$ 11 What happens when bromine water is added to a saturated hydrocarbon and an unsaturated hydrocarbon? There is no change with either hydrocarbon The saturated hydrocarbon changes the bromine water from brown to colourless The unsaturated hydrocarbon changes the bromine water from brown to colourless. 12 Which of the following will undergo an addition reaction with chlorine? Butane Pent-2-ene Benzene 13 What is the expected product formed from the reaction between 2-butene and chlorine? 1-chlorobutane 2,2-dichlorobutane 2-chlorobutane 2,3-dichlorobutane 14 The representation CH3−CH2−CH2−CH2−CH3$$C{H}_3-C{H}_2-C{H}_2-C{H}_2-C{H}_3$$ for the alkane pentane is an example of ____________ a molecular formula a condensed structural formula an expanded structural formula a skeletal structural formula 15 Which of these statements is true? Ethyne will dissolve in water and cyclohexane Ethyne will dissolve in water and dilute hydrochloric acid Ethyne will dissolve in cyclohexane and methyl benzene All of the above 16 Ethyne gas may be tested for saturation in the laboratory. Which of these is a positive test? It changes the colour of cobalt chloride paper from blue to pink It changes the colour of bromine water from red to blue It turns lime water milky It decolorizes acidified potassium permanganate solution. 17 Which molecule contains a total of three carbon atoms? 2-methyl propane 2-methyl butane Propane Butane 18 Breaking of a larger hydrocarbon molecule into a smaller one by heating in the presence of a catalyst is called ___. Cracking Orthofugation Centrifugation Thermogenation 19 An isomer of pentane is ___________. 2,2-Dimethylpropane 2,2-Dimethylpentane 1,1-Dimethylcyclopropane 2,3-Dimethylbutane 20 Isomers have the same _____________. Melting point Molecular formula Boiling point Reactivity