Question

Complete and balance the following equations:
A. $C + {H_2}S{O_4}(conc) \to$
B. $Xe{F_2} + P{F_5} \to$

Answer 1

An equation is balanced when the same number of each element is represented on the reactant and product sides. Balancing the equation may be confirmed by simply summing the numbers of atoms on either side of the arrow and comparing these sums to ensure they are equal.

Complete answer:
First of all, let’s complete the first chemical equations.
When carbon reacts with concentrated sulfuric acid then it produces carbon dioxide and sulfur dioxide along with water.
$C + {H_2}S{O_4} \to C{O_2} + S{O_2} + {H_2}O$
Now, let’s balance the above equation. We can see that the number of carbon atoms is the same on both reactant and product side. The number of hydrogen atoms and sulfur atoms is also the same on both sides. The number of oxygen atoms is, however, different. There are $4$ oxygen atoms on the reactant side and $5$ on the products side. Let’s multiply the water molecule by $2$. Now the equation becomes:
$C + {H_2}S{O_4} \to C{O_2} + S{O_2} + 2{H_2}O$
This however disbalances the number of hydrogen atoms. To balance it again, we will multiply the sulphuric acid molecule by $2$ as well. Hence, the equation becomes:
$C + 2{H_2}S{O_4} \to C{O_2} + S{O_2} + 2{H_2}O$
Now to finally balance the sulphur and oxygen atoms we will simply multiply by $2$. Hence, the final balanced equation is:
$C + 2{H_2}S{O_4} \to C{O_2} + 2S{O_2} + 2{H_2}O$
Now let’s complete the second chemical equation.
When xenon difluoride reacts with phosphorus pentafluoride then it creates xenon fluoride ion hexafluorophosphate ion.
$Xe{F_2} + P{F_5} \to Xe{F^ + } + PF_6^ -$
The total number of atoms of all the elements remains the same as the reaction is a double displacement reaction. Hence, no balancing is required.

Note:
The balancing of equations is important as it reflects the law of conservation of mass and hence should be done accurately. The law of conservation of mass states that mass can neither be created nor be destroyed.
While balancing the chemical equations, remember to not change the subscripts of the molecule or the atom as it changes the whole molecule to a different compound.