Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.
Electrons enter into orbitals in order of increasing energy as exemplified by?
1S\(^2\)2S\(^2\)2PX\(^2\)2py\(^2\)2pz\(^0\)3s\(^0\)
1S\(^2\)2S\(^2\)2PX\(^2\)2py\(^1\)2pz\(^1\)3s\(^0\)
1S\(^2\)2S\(^2\)2PX\(^1\)2py\(^1\)2pz\(^1\)3s\(^1\)
1S\(^2\)2S\(^2\)2PX\(^2\)2py\(^2\)2pz\(^0\)3s\(^1\)
Correct answer is B
Shells and subshells are filled in energy level order, so electrons will fill the 2p subshell before the 3s shell.
And the x subshell before the y and z.
H\(^+\) + OH\(^-\) → H\(_2\)O The equation above illustrates
precipitation
hydration
hydrolysis
neutralization
Correct answer is D
A neutralization reaction is when an acid and a base react to form water and a salt and involves the combination of H+ ions and OH- ions to generate water.
Which of the following best represent solid gas mixture?
milk
kerosene
soil
smoke
Correct answer is D
Solid in gas mixture: Smoke, ice clouds, dust.
Liquid in gas mixture: fog, mist, vapour and hair sprays.
Gas in solid mixture: aerogel, Styrofoam.
When heat is absorbed during a chemical reaction, the reaction is said to be
thermodynamic
exothermic
isothermal
endothermic
Correct answer is D
An endothermic reaction is any chemical reaction that absorbs heat from its environment.
The dehydration of CH\(_3\)CH\(_2\)CH\(_2\)CH\(_2\)OH will give?
HC≡CCH\(_2\)CH\(_3\)
CH\(_2\)≡CH\(_2\)CH\(_3\)
CH\(_3\)C≡CCH\(_3\)
CH\(_3\)CH=CHCH\(_3\)
Correct answer is D
An alkene is produced when dehydration of alcohol is performed. Alcohol dehydration is an example of an elimination reaction which is quite the opposite of substitution reaction and addition reaction.
The products of the dehydration of a primary alkanol are water and an alk-1-ene (1-alkene).
Butanol gives a mixture of but-1-ene and but-2-ene when dehydrated.