Question

In a chemical reaction, sum of formula weight of all reactants is 274 u and atom economy is 50%, calculate formula weight of desired product?

• A. 137 u
• B. 274 u
• C. 167 u
• D. 254 u

Hint:

Atom economy = useful product fraction; 50% means half of reactant mass forms product.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Atom economy is a principle of green chemistry that measures how much of the starting materials end up in the desired product.
Step 2: Key Formula or Approach:
\[ \text{Atom Economy (%)} = \frac{\text{Formula weight of desired product}}{\text{Sum of formula weights of all reactants}} \times 100 \] Step 3: Detailed Explanation:
Given:
Sum of reactant weights = \(274\text{ u}\)
Atom economy = \(50%\)
Let $P$ be the weight of the desired product.
\[ 50 = \frac{P}{274} \times 100 \] \[ 0.5 = \frac{P}{274} \] \[ P = 0.5 \times 274 = 137\text{ u} \] Step 4: Final Answer:
The formula weight is $137$ u.