A two-step reaction is shown below - Scottish Highers Chemistry - Question 19 - 2019

To calculate the overall yield of a two-step reaction, we use the formula for combined yields:

1. Determine the yield from the first step:

   • Yield from Step 1 = 60% = 0.60

2. Determine the yield from the second step:

   • Yield from Step 2 = 90% = 0.90

3. The overall yield can be calculated using: $ext{Overall Yield} = ext{Yield from Step 1} \times ext{Yield from Step 2}$

   • Substitute the values: $ext{Overall Yield} = 0.60 \times 0.90 = 0.54$

4. Convert this value to a percentage:

   • Overall Yield = 0.54 × 100 = 54%

Therefore, the overall yield of the reaction is 54%, corresponding to option B.