Questions: Balance the following equation with the smallest whole number coefficients. When balanced, what is the coefficient for B (in the reactants)?
Sc2O3 + ... B → ScB2 + ... BO
a) 1
b) 3
c) 5
d) 7
e) 9
Transcript text: Balance the following equation with the smallest whole number coefficients. When balanced, what is the coefficient for B (in the reactants)?
\[
{ }_{-} \mathrm{Sc}_{2} \mathrm{O}_{3}+\ldots \mathrm{B} \rightarrow \_\mathrm{ScB}_{2}+\ldots \mathrm{BO}
\]
a) 1
b) 3
c) 5
d) 7
e) 9
Each \(\mathrm{ScB}_2\) contains 2 boron atoms, and there are 2 \(\mathrm{ScB}_2\) on the right side, giving a total of \(2 \times 2 = 4\) boron atoms. Additionally, there are \(z\) boron atoms in \(\mathrm{BO}\). Therefore, the total number of boron atoms on the right side is \(4 + z\).
To balance boron, we set the number of boron atoms on the left side equal to the number on the right side:
\[
x = 4 + z
\]
Step 4: Balance Oxygen (O)
There are 3 oxygen atoms on the left side in \(\mathrm{Sc}_2\mathrm{O}_3\). Each \(\mathrm{BO}\) contains 1 oxygen atom, so to balance oxygen, we need:
\[
z = 3
\]
Step 5: Solve for Boron Coefficient
Substitute \(z = 3\) into the boron balance equation:
\[
x = 4 + 3 = 7
\]
Final Answer
The coefficient for boron (B) in the reactants is \(\boxed{7}\).