21 questions
The oxidation state of selenium in NaSeO₃ is
+5
+3
+7
-5
In the reaction 2Ca(s) + O₂(g) --> 2CaO(s), calcium is __________
reduced
oxidized
electrolyzed
synthesized
In the reaction N₂(g) + 3 H₂(g) --> 2 NH₃(g), nitrogen is __________.
reduced
oxidized
electrolyzed
synthesized
Oxygen usually has an oxidation number of ___ when it is combined with other elements in a compound.
+6
-6
+2
-2
Elements not combined with other elements in a compound have an oxidation number of ____.
Depends on their group on the periodic table
+1
0
= to the number of valence elections
Oxidation is the loss of electron, meaning, there is an increase of oxidation number
True
False
The species that loses electron is _____ and usually _____ agent.
oxidized;reducing
reduced;oxidizing
oxidized;oxidizing
reduced;reducing
+3
-5
+5
-3
-2
+2
-6
+6
-1
+7
+1
-7
-1
+1
-4
+4
The ionic equation represents a redox reaction. Which of the following statement is correct?
Oxygen is the reducing agent.
The oxidation number of hydrogen increases from +1 to +2.
The manganate(VII) ions, MnO4- has been oxidized.
The manganate(VII) ions, MnO4- has been reduced.
What is the oxidation number for iodine molecules?
1
-1
2
0
What is the oxidation number for magnesium ion?
0
+2
+1
Reaction between nitric acid and sodium hydroxide is a redox reaction.
TRUE
FALSE
Determine the oxidation number of nitrogen ,N in KNO3
0
-3
+5
Reaction between lead nitrate and sodium sulphate produces lead sulphate and sodium nitrate. Therefore, this reaction is a redox reaction
TRUE
FALSE
What is the oxidation number of titanium,Ti in titanium dioxide,TiO2 ?
0
+2
+4
Magnesium metal can react with zinc chloride to form magnesium chloride and zinc metal. Select the correct statments.
The type of reaction is displacement reaction.
The type of reaction is substitution reaction.
Magnesium undergoes oxidation.
Zinc metal undergoes reduction.
Chemical equation : Zn + CuO --> ZnO + Cu
which statements are true?
Copper ion undergoes oxidation
Zinc metal undergoes oxidation
Oxidation number of zinc increases from 0 to +2
Copper ion in CuO acts as oxidizing agent.
Half equation : Br2 + 2e- --> 2Br-
Which statement is correct?
Bromine undergoes oxidation
Bromine undergoes reduction