Using proportions from the chemical equation 🧮
French version 🇫🇷
Complete combustion of methane 🔥
Word equation:
Methane + Dioxygen → Carbon dioxide + Water
Chemical equation:
CH
4
+
2
O
2
→ CO
2
+
2
H
2
O
Question 1
75 methane molecules are burnt.
How many dioxygen molecules are
needed?
Hint 💡: Use the proportions given by the balanced chemical equation.
CH
4
O
2
Chemical equation
Calculation:
Result:
Conclusion:
?
dioxygen molecules (O
2
) are needed.
Question 2
45 methane molecules are burnt.
How many water molecules H
2
O
appear?
CH
4
H
2
O
Chemical equation
Calculation:
Result:
Conclusion:
?
water molecules (H
2
O) appear.
1
2
75
?
2×75/1
2/1×75
2×75
75×2/1
75/1×2
75×2
2*75/1
2/1*75
2*75
75*2/1
75/1*2
75*2
\( \mathsf { \displaystyle\frac{75 \times 2}{1} } \)
150
1
2
45
?
2×45/1
2/1×45
2×45
45×2/1
45/1×2
2*45/1
2/1*45
2/1*45
2*45
45*2/1
45/1*2
45*2
\( \mathsf { \displaystyle\frac{45 \times 2}{1} } \)
90
📊 RESULT:
Next exercise 🔀