Answer: Option (B) is the correct answer.
Explanation:
It is known that for writing a chemical reaction equation, reactants are written on left hand side whereas products are written on right hand side.
And in between reactants and products a forward arrow is placed pointing towards the products.
Therefore, the reaction for carbon burns in the presence of oxygen to give carbon dioxide will be written as follows.

Here, carbon and oxygen atoms are the reactants whereas carbon dioxide is the product.
Answer:
43.5 moles of HNO₃.
Explanation:
The balanced equation for the reaction is given below:
S + 6HNO₃ —> H₂SO₄ + 6NO₂ + 2H₂O
From the balanced equation above,
6 moles of HNO₃ reacted to produce 2 moles of H₂O.
Finally, we shall determine the number of mole of HNO₃ required to produce 14.5 moles of H₂O.
This can be obtained as illustrated below:
From the balanced equation above,
6 moles of HNO₃ reacted to produce 2 moles of H₂O.
Therefore, Xmol of HNO₃ will react to produce 14.5 moles of H₂O i.e
Xmol of HNO₃ = (6 × 14.5)/2
Xmol of HNO₃ = 43.5 moles
Therefore, 43.5 moles of HNO₃ is required to produce 14.5 moles of H₂O.
Answer:
AlN has highest melting point among given.
Explanation:
As per ionic model, ionic compounds are held together by electrostatic force. The ionic compound having strong electrostatic force will have high melting point.
Electrostatic force is proportional to charge and size of constituent ions.

In case of MgO
Charge on Mg = +2
Charge on O = -2

In case of LiF
Charge on Li = +1
Charge on F = -1

In case of AlN
Charge on Al = +3
Charge on N = -3

In case of RbF
Charge on Rb = +1
Charge on F = -1

In case of CaS
Charge on Ca = +2
Charge on S = -2

As magnitude of electrostatic force is highest in AlN, therefor, it has highest melting point.
Poler covalent
again don’t quote me on it i’m just trying my best with what i remember