Which of the following CANNOT be obtained by fractional distillation of petroleum?
Ether
Methane
Butane
Ethene
Hydrogen
Correct answer is E
The fractional distillation of crude oil gives several products in liquid and gaseous forms. The products that are in the gaseous form include petroleum gas or LPG (liquefied petroleum gas) e.g. methane, ethane, propane, butane, propylene, butylene, propane, etc.
Therefore the answer to this question is hydrogen.
In the reaction NH3 + H+ → NH4+, the bond formed results from?
an electron transferred from NH3 + H+
an electron pair donated by NH3
an electron pair equally shared
an electron pair donated by H+
an electron tarnsferred from H+ to NH3
Correct answer is B
The nitrogen atom has a lone pair of electrons that coordinates to the hydrogen cation, which has zero electrons, forming a covalent bond.
Which of the following statements is incorrect?
Calcium reacts with water to form calcium
Magnesium reacts very slowly with water but faster with warm water
Iron will not react with water in the absence of air
Sodium reacts with water
Copper reacts with steam
Correct answer is E
No explanation has been provided for this answer.
deliquescence
hygroscopy
oxidation
efforescence
sublimation
Correct answer is D
No explanation has been provided for this answer.
sodium
chlorine
hydrogen
sodium hydroxide
oxygen
Correct answer is C
During the electrolysis of NaCl using carbon electrodes, hydrogen is usually deposited at the cathode because hydrogen is less reactive and lower than sodium in the electrochemical series(sodium and hydrogen are the two cations in the solution)