Chemistry Past Questions And Answers
The decarboxylation of ethanoic acid will produce carbon (IV)oxide and
- A) methane
- B) ethane
- C) propane
- D) butane
A chloroform solution of pure organic compound was spotted at a distance 0.80cm from the base of a 20cm long chromatoplate. If the compound has the \(r_f\)-value of 0.505 and moves half way up the 20cm long plate, which is the distance of the solvent front from the top of the plate upon elution?
- A) 0.80cm
- B) 1.0cm
- C) 1.2cm
- D) 1.4cm
A metallic ion Z2+ with an inert gas structure contains 18 electrons. How many protons are contained in this ion?
- A. 20
- B. 18
- C. 16
- D. 2
1s2, 2s2, 2p6, 3s2, 3p6, 3d7, 4s2 An element with the electronic configuration above is a
- A. non-metal
- B. metal
- C. transition element
- D. group two element
An exothermic reaction is one which involves
- A. attainment of dynamic equilibrium
- B. loss of heat to the surrounding
- C. evolution of gas as it proceeds
- D. positive change in value of enthalpy
The mass spectrometer can be used to measure mass of
- A. an atom
- B. an electron
- C. a proton
- D. a neutron
When heat is absorbed during a chemical reaction, the reaction is said to be _______
- A) thermodynamic
- B) exothermal
- C) isothermal
- D) endothermic
The gas that is the most dangerous pollutant to human is
- A. sulphur (IV) oxide
- B. carbon (IV) oxide
- C. nitrogen (II) oxide
- D. hydrogen sulphide
What quantity of current is required to deposit 2.4g of copper in a period of 750 seconds during an electrolytic deposition process? [Cu 64, IF = 96500C mol?1]
- A) 9.65A
- B) 10.81A
- C) 12.33A
- D) 15.54A
Electrovalent compounds normally ------------
- A. have low boiling points
- B. have mobile electrons
- C. conduct electricity in the solid state
- D. dissolve in polar solvent