Answer:
Answer below
Explanation:
A - false
B - true
C - false
In chemistry there is a principle that polar compounds are soluble with other polar compounds and non-polar compounds are mutually different.
Thus, sodium chloride is an ionic salt (polar) so it is not soluble in the benzene (non-polar) covalent compound, but it is soluble in water that is polar.
The ionic compounds will be soluble in polar solvents and not soluble in non-polar solvents, regardless of whether they are organic or inorganic.
Let's define an ionic and covalent bond.
An ionic bond occurs between a metal and non-metal. These electrons are transferred between atoms. A Covalent bond occurs between a nonmetal and a nonmetal. These electrons are shared between atoms.
First, identify whether each element is metal or nonmetal. If you need a little help, refer to an online periodic table for guidance.
We see that both Hydrogen and Sulfur are nonmetals. That eliminates both choice 1 and 3.
Then, understanding that within covalent bonds, electrons are shared, choice 4 is eliminated.
Thus, the answer is 2.
Answer: Option (d) is the correct answer.
Explanation:
A reaction in which there occurs change in oxidation state of reacting species is known as an oxidation-reduction reaction.
(a)
Will be written as:

In this reaction, there occurs no change in oxidation state of reacting species. Hence, it is not an oxidation-reduction reaction.
(b) 
Will be written as:

Similarly here, there occurs no change in oxidation state of reacting species. Hence, it is not an oxidation-reduction reaction.
(c) 
Will be written as:

Here, also there occurs no change in oxidation state of reacting species. Hence, it is not an oxidation-reduction reaction.
(d) 
So, here there occurs change in oxidation state of Mg from 0 to +2 and oxidation state of H changes from +1 to 0. Hence, it is an oxidation-reduction reaction.
Thus, we can conclude that
is an oxidation-reduction reaction.
I hope I am right on this, but the answer is
Fe₂O₃ + 3CO --> 2Fe + 3CO₃