Select the correct answer.
Which is a balanced chemical equation?
A. $C _7 H _{16}+5 O _2 \rightarrow 6 CO _2+4 H _2 O$
B. $C _7 H _{16}+11 O _2 \rightarrow 7 CO _2+8 H _2 O$
C. $C _7 H _{16}+14 O _2 \rightarrow 7 CO _2+5 H _2 O$
D. $C _7 H _{16}+22 O _2 \rightarrow 14 CO _2+16 H _2 O$
Answer (1)
Check each equation to see if the number of atoms of each element is the same on both sides.
In option A, the number of C and H atoms are not balanced.
In option B, the number of C, H, and O atoms are balanced.
In option C, the number of H and O atoms are not balanced.
In option D, the number of C and H atoms are not balanced. The balanced chemical equation is C 7 H 16 + 11 O 2 → 7 C O 2 + 8 H 2 O .
Explanation
Understanding the Problem We need to determine which of the given chemical equations is balanced. A balanced chemical equation has the same number of atoms of each element on both sides of the equation. We will check each option.
Checking Option A A. C 7 H 16 + 5 O 2 → 6 C O 2 + 4 H 2 O Reactant side: 7 C, 16 H, 10 O Product side: 6 C, 8 H, 12+4 = 16 O This equation is not balanced.
Checking Option B B. C 7 H 16 + 11 O 2 → 7 C O 2 + 8 H 2 O Reactant side: 7 C, 16 H, 22 O Product side: 7 C, 16 H, 14+8 = 22 O This equation is balanced.
Checking Option C C. C 7 H 16 + 14 O 2 → 7 C O 2 + 5 H 2 O Reactant side: 7 C, 16 H, 28 O Product side: 7 C, 10 H, 14+5 = 19 O This equation is not balanced.
Checking Option D D. C 7 H 16 + 22 O 2 → 14 C O 2 + 16 H 2 O Reactant side: 7 C, 16 H, 44 O Product side: 14 C, 32 H, 28+16 = 44 O This equation is not balanced.
Final Answer The balanced chemical equation is B. C 7 H 16 + 11 O 2 → 7 C O 2 + 8 H 2 O
Examples
Balancing chemical equations is essential in various real-world applications, such as calculating the amount of reactants needed for a chemical reaction or determining the products formed. For instance, in the combustion of fuels like heptane ( C 7 H 16 ), a balanced equation ensures that we know exactly how much oxygen is required to completely burn the fuel, preventing the formation of harmful byproducts like carbon monoxide. This is crucial in designing efficient engines and reducing air pollution.
