Question

When the following equation is balanced with the smallest possible integer coefficients, what is the coefficient of H+?

Answer 1

D. 6

Step-by-step explanation

Given that:

`Cr+H^+\rightarrow Cr^(3+)+H_2`

What to find:

The coefficient of H⁺ when the given equation is balanced with the smallest possible integer coefficients.

Solution:

The given equation is an example of an oxidation-reduction (redox) reaction

The first step is to identify the half equations:

`\begin{gathered} Oxidation:Cr\rightarrow Cr^(3+) \\ \\ Reduction:H^+\rightarrow H_2 \end{gathered}`

The next step is to balance the half equations molecularly follow by balancing the charge:

`\begin{gathered} Oxidation:Cr\rightarrow Cr^(3+)+3e^-*2 \\ \\ Reduction:2H^++2e^-\rightarrow H_2*3 \\ \\ Multiply\text{ }oxidation\text{ }half\text{ }equation\text{ }by\text{ }2\text{ }and\text{ }reduction\text{ }halfe\text{ }quation\text{ }by\text{ }3 \\ \\ Ox\imaginaryI dat\imaginaryI on:2Cr\rightarrow2Cr^(3+)+6e^- \\ \\ Reduction:6H^++6e^-\rightarrow3H_2 \end{gathered}`

The final step is to combine the half equations and simplified:

`2Cr+6H^+\rightarrow2Cr^(3+)+3H_2`

Therefore, the coefficient of H⁺ in the balanced equation above is 6.

The correct answer is D. 6