Chemistry_2014_STPM term 3_Objectives

Which molecule has carbon atoms with sp hybrid orbitals?

• CH ≡ CH

• CH₂ = CH₂

• CH₃ = CH₃

• C₆ H₆

Combustion of hydrocarbon X in excess oxygen produces 0.66g of dioxide and 0.27g of water. At room temperature and pressure, X is a gas with density 1.75g dm^-3 . What could the molecular formula of X be?

[ The relative atomic mass : C = 12, H = 1; 1 mol of gas occupies 24 dm³ at room temperature and pressure.]

• C₂H₄

• C₂H₆

• C₃H₆

• C₄H₈

What is the IUPAC name of the organic compound below?

• 2-Ethyl -1- hydroxy-1-hexenoic acid

• 3-Ethyl -2- hydroxy-2-hexenoic acid

• 2-Hydroxy-3- propyl-2-pentenoic acid

• 4-Hydroxy-3- propyl-3-pentenoic acid

What type of stereoisomerism is shown by each compound?

• Ⅰ : Geometrical

  Ⅱ : Geometrical

  Ⅲ : Optical

• Ⅰ : Geometrical

  Ⅱ : Optical

  Ⅲ : Geometrical

• Ⅰ : Optical

  Ⅱ : Geometrical

  Ⅲ : Optical

• Ⅰ : Optical

  Ⅱ : Optical

  Ⅲ : Geometrical

Which is the sequence of the acid according to the ascending order based on their pK_a values?

• Ⅰ , Ⅱ , Ⅲ

• Ⅰ , Ⅲ , Ⅱ

• Ⅱ , Ⅲ , Ⅰ

• Ⅲ , Ⅱ , Ⅰ

Which of the carbon atoms labelled w, x, y and z undergoes electrophilic addition?

• w

• x

• y

• z

Which reagent can be used to distinguish nitrobenzene from toluene?

• H₂SO

• Br₂∕FeBr₃

• KMnO₄∕H⁺ , ∆

• CH₃COCl∕AlCl₃

• 
• 
• 
• 

Organic compounds R and S have the same functional group. The chemical properties of R and S are as follows:

(ⅰ) R and S react with KMnO₄∕H⁺

(ⅱ) R forms a yellow precipitate with alkaline iodine but S does not.

Which are the possible structural formulae of R and S?

• R : CH₃CHO

  S : CH₃COOH

• R : CH₃COOH

  S : CH₃CH₂COOH

• R : CH₃CH₂OH

  S : (CH₃)₃COH

• 

Which reaction does not produce hydroxyl compound?

• Fermentation of sugar

• Propanenitrile with mineral acid under reflex

• Propene with cold alkaline potassium manganate (Ⅶ) solution

• Methanal with Grignard reagent in dry ether followed by hydrolysis