Using proportions from chemical equations 🧮
French version 🇫🇷
Rust formation 🧲
Word equation:
Iron + Dioxygen → Iron(III) oxide
Chemical equation:
4
Fe +
3
O
2
→
2
Fe
2
O
3
Question 1
When 100 iron atoms react to form rust.
How many dioxygen molecules are
needed?
Fe
O
2
Chemical equation
Calculation:
Result:
Conclusion:
?
dioxygen molecules are needed.
Question 2
How many iron oxide molecules can be obtained with 90 dioxygen molecules?
O
2
Fe
2
O
3
Chemical equation
Calculation:
Result:
Conclusion:
?
iron(III) oxide molecules Fe
2
O
3
can be obtained.
4
3
100
?
3×100/4
3/4×100
100×3/4
100/4×3
3*100/4
3/4*100
100*3/4
100/4*3
\( \mathrm { \displaystyle\frac{100 \times 3}{4} } \)
75
3
2
90
?
2×90/3
2/3×90
90/3×2
90×2/3
2*90/3
2/3*90
90/3*2
90*2/3
\( \mathsf { \displaystyle\frac{90 \times 2}{3} } \)
60
📊 RESULT:
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