Question
The symbol equation for aerobic respiration is shown.
\[ \text{C}_6\text{H}_x\text{O}_y + 6\text{O}_2 \rightarrow 6\text{CO}_2 + 6\text{H}_2\text{O} \]
Which numbers represent the letters shown in the equation as x, y and z?
| x | y | z | |
|---|---|---|---|
| A | 2 | 12 | 6 |
| B | 6 | 2 | 12 |
| C | 6 | 12 | 2 |
| D | 12 | 6 | 2 |
▶️ Answer/Explanation
Solution
Ans: D
The correct formula for glucose is C6H12O6, so x=12, y=6. The equation is already balanced with z=2 (6H2O). Therefore, the correct combination is D.
Question
How many molecules of carbon dioxide, glucose, oxygen and water are there in the balanced chemical equation for aerobic respiration?
▶️ Answer/Explanation
Solution
Ans: C
The balanced chemical equation for aerobic respiration is:
C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy
This shows:
- 1 molecule of glucose (C6H12O6).
- 6 molecules of oxygen (O2).
- 6 molecules of carbon dioxide (CO2).
- 6 molecules of water (H2O).
Only Option C matches these quantities. The other options either miscount the molecules or misrepresent the equation.