Question

Which one of the following is a balanced equation?
A. $Na\text{ }\left( s \right)\text{ }+\text{ }{{O}_{2}}\text{ }\left( g \right)\text{ }\to \text{ }N{{a}_{2}}O$
B. $Zn\text{ }\left( s \right)\text{ }+\text{ }HCl\text{ }\left( g \right)\text{ }\to \text{ }ZnC{{l}_{2}}\text{ }\left( s \right)\text{ }+\text{ }{{H}_{2}}\text{ }\left( g \right)$
C. $Na\text{ }\left( s \right)\text{ }+\text{ }Mg{{F}_{2}}\text{ }\to \text{ }2NaF\text{ }\left( s \right)\text{ }+\text{ }Mg\text{ }\left( s \right)$
D. $2Na\text{ }\left( s \right)\text{ }+\text{ }Mg{{F}_{2}}\text{ }\to \text{ }2NaF\text{ }\left( s \right)\text{ }+\text{ }Mg\text{ }\left( s \right)$

Answer 1

A chemical reaction is a process that results in the chemical change of one set of chemical substances into another set of chemical substances. Chemical reactions are often defined as changes in the locations of electrons in the formation and breaking of chemical bonds between atoms, with no change in the nuclei (no change in the elements present), and may be represented using a chemical equation.

Complete answer:
On the reactant and product sides of a balanced chemical equation, there are equal quantities of atoms for each element involved in the reaction. This is a condition that the equation must meet in order to be compatible with the conservation of matter rule. It may be verified by adding the numbers of atoms on both sides of the arrow and comparing them to check that they are equal. Note that the number of atoms in any formula involving that element is computed by multiplying the coefficient by the element's subscript in the expression.
If an element appears in several formulas on one side of an equation, the number of atoms represented in each must be calculated and then added.
If you were given this problem while getting change for a monetary transaction, you would know the correct solution right away.
Equilibrium of mass and mass with regard to products and reactants are required in a balanced chemical equation.
We were able to
A. $\mathrm{Na}(\mathrm{s})+\mathrm{O}_{2}(\mathrm{~g}) \rightarrow \mathrm{Na}_{2} \mathrm{O}(\mathrm{s})$ Is not the balanced chemical equation
the balanced chemical equation is $2 N a(s)+\dfrac{1}{2} O_{2}(g) \rightarrow N a_{2} O(s)$
B. $\text{Zn}(\text{s})+\text{HCl}(\text{aq})\to \text{ZnC}{{\text{l}}_{2}}(aq)+{{H}_{2}}$ Is not the balanced chemical equation
the balanced chemical equation is $Z n(s)+2 H C l(a q) \rightarrow Z n C l_{2}(a q)+H_{2}(g)$
C. $\text{Na}(\text{s})+\text{Mg}{{\text{F}}_{2}}(~\text{s})\overset{\Delta }{\mathop{\to }}\,2\text{NaF}(s)+Mg$ Is not the balanced chemical equation
the balanced chemical equation is
$2\text{Na}(s)+Mg{{F}_{2}}(s)\overset{\Delta }{\mathop{\to }}\,2NaF(s)+Mg(s)$
D. $2\text{Na}(\text{s})+\text{Mg}{{\text{F}}_{2}}(s)\overset{\Delta }{\mathop{\to }}\,2\text{NaF}(s)+Mg(s)$
Both Mass and Charge are CONSERVED...we've got a winner...mass and charge, like any actual chemical process, are stoichiometrically balanced.

Hence option d Is correct.
since both sides of the equation have the same number of each element ( 2 Na atoms on both the left hand and the right hand side, 1 Mg atom on each side, and 2 F atoms on each side)

Note:
Reactants or reagents are the chemicals (or substances) that are initially involved in a chemical reaction. Chemical reactions generally involve a chemical change and the formation of one or more products with characteristics distinct from the reactants. The information on the specific path of action is part of the reaction mechanism, which frequently consists of a succession of discrete sub-steps, referred to as elementary reactions.