Multiple Choice
Which of the following is the correctly balanced chemical equation for the reaction: Ag(s) + CN⁻(aq) + O₂(g) → Ag(CN)₂⁻(aq)?
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3. Chemical Reactions
Balancing Chemical Equations
Multiple Choice
Which set of coefficients correctly balances the chemical equation: __C_2H_6 + __O_2 → __CO_2 + __H_2O?
A
2, 6, 4, 6
B
1, 3, 2, 3
C
1, 2, 2, 2
D
2, 7, 4, 6
Verified step by step guidance1
Write down the unbalanced chemical equation: \(\_\_ C_2H_6 + \_\_ O_2 \rightarrow \_\_ CO_2 + \_\_ H_2O\).
Assign variables to the coefficients: let the coefficients be \(a\) for \(C_2H_6\), \(b\) for \(O_2\), \(c\) for \(CO_2\), and \(d\) for \(H_2O\).
Balance carbon atoms first: since there are 2 carbons in \(C_2H_6\), set \(c = 2a\) to balance carbon atoms on both sides.
Balance hydrogen atoms next: there are 6 hydrogens in \(C_2H_6\), so set \(d = \frac{6a}{2} = 3a\) to balance hydrogen atoms (each \(H_2O\) has 2 hydrogens).
Balance oxygen atoms last: total oxygen atoms on the right are \$2c + d = 2(2a) + 3a = 4a + 3a = 7a\(. Since each \)O_2$ molecule has 2 oxygen atoms, set \(b = \frac{7a}{2}\). To avoid fractions, multiply all coefficients by 2 to get whole numbers.
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