Answer:
.
One chlorine molecule reacts with two formula units of (aqueous) potassium bromide to produce one bromine molecule and two formula units of (aqueous) potassium chloride.
Explanation:
<h3>Formula for each of the species</h3>Start by finding the formula for each of the compound.
- Both chlorine
and bromine
are group 17 elements (halogens.) Each
- On the other hand, potassium
is a group 1 element (alkaline metal.) Each
Therefore, the ratio between atoms and
atoms in potassium bromide is supposed to be one-to-one. That corresponds to the empirical formula
. Similarly, the ratio between
The formula for chlorine gas is , while the formula for bromine gas is
.
Write down the equation using these chemical formulas.
.
Start by assuming that the coefficient of compound with the largest number of elements is one. In this particular equation, both and
features two elements each.
Assume that the coefficient of is one. Hence:
.
Note that is the only source of
and
atoms among the reactants of this reaction.
There would thus be one atom and one
atom on the reactant side of the equation.
Because atoms are conserved in a chemical equation, there should be the same number of and
atoms on the product side of the equation.
In this reaction, is the only product with
atoms.
One atom would correspond to
units of
.
Similarly, in this reaction, is the only product with
atoms.
One atom would correspond to one formula unit of
.
Hence:
.
Similarly, there should be exactly one atom on either side of this equation. The coefficient of
should thus be
. Hence:
.
That does not meet the requirements, because two of these coefficients are not integers. Multiply all these coefficients by two (the least common multiple- LCM- of these two denominators) to obtain:
.