Aluminium burns in oxygen: . When the equation is balanced with the smallest whole numbers, what is the sum of all the coefficients?
Answer and explanation
Correct answer: A.
- Step 1: Balance oxygen first: gives O atoms, which need .
- Step 2: Then aluminium atoms are needed: .
- Step 3: Sum .
Answer
.
Why not the others: : leaves out the coefficient of the product. : counts the unbalanced equation, where every coefficient is . : uses doubled coefficients, which are not the smallest.
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