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.
Which of the following methods can be used to seperate blood cells from plasma?
Centrifugation
Filtration
Chromatography
Distillation
Correct answer is A
No explanation has been provided for this answer.
+2 to +3
0 to +2
+3 to +2
+3 to 0
Correct answer is C
The oxidation number of Iron in \(FeCl_{3}\) = +3. The oxidation number in \(FeCl_{2}\) = +2.
The empirical formula of a compound containing 0.067mol Cu and 0.066mol O is [Cu = 63.5, O = 16]
\(Cu_{2}O\)
\(CuO\)
\(CuO_{2}\)
\(CuO_{4}\)
Correct answer is B
Cu : O
0.067 : 0.066
mole ratio \(\frac{0.067}{0.066}\) : \(\frac{0.066}{0.066}\)
= 1 : 1
= CuO
oxidised
reduced
decomposed
dissociated
Correct answer is A
Reaction: \(2AgNO_{3} + Zn \to Zn(NO_{3})_{2} + 2Ag\)
The oxidation number of Zn in the reactant is 0, and in the product is +2. Therefor, it is oxidized.
The strength of metallic bonds depends on the
charge density of the atoms
ductility of the metal
number of valence electrons
total number of electrons in the atom
Correct answer is C
It is determined by the difference in the electron structures of the atoms. These primarily are: The number of outer electrons, i.e the number of valence shell electrons released during a metallic bond.