Answer : The Lewis-dot structure of
is shown below.
Explanation :
Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule.
In the Lewis-dot structure the valance electrons are shown by 'dot'.
The given molecule is, 
As we know that carbon has '4' valence electrons, chlorine has '7' valence electron and oxygen has '6' valence electrons.
Therefore, the total number of valence electrons in
= 1(4) + 2(7) + 1(6) = 24
According to Lewis-dot structure, there are 8 number of bonding electrons and 16 number of non-bonding electrons.
Answer : The change in internal energy is, 900 Joules.
Solution : Given,
Heat given to the system = +1400 J
Work done by the system = -500 J
Change in internal energy is equal to the sum of heat energy and work done.
Formula used :

where,
= change in internal energy
q = heat energy
w = work done
As per question, heat is added to the system that means, q is positive and work done by the system that means, w is negative.
Now put all the given values in the above formula, we get

Therefore, the change in internal energy is 900 J.
The change in internal energy depends on the heat energy and work done. As we will change in the heat energy and work done, then changes will occur in the internal energy. Hence, the energy is conserved.
Answer: FeO is called ferrous oxide while Fe2O3 is ferric oxide
Explanation:
Ferrous oxide, commonly known as iron(II) oxide contains iron that lost 2 elections in the oxidation process. So it is able to bond with other atoms that have an extra 2 electrons to share. Ferric oxide, is commonly known as iron(III) oxide
Answer:
I'm so sorry if this is wrong but I think its B
Answer: 4. A solution in which methyl orange is red
Explanation:
The others solutions are in their basic form while methyl orange is in it’s acidic form when red.