For the sequential reactions:
`2A overset(80%)to 3B + C`
`2B overset(50%)to 5D + E`
Moles of A needed for the formation of 1.5 moles of D is:

Options

A. 0.6
B. 0.4
C. 1
D. 1.16

Answer

To solve the problem of how many moles of A are needed for the formation of 1.5 moles of D through the given sequential reactions, we can break it down step by step.

### Step 1: Understand the first reaction
The first reaction is:
\[ 2A \overset{80\%}{\rightarrow} 3B + C \]

From this reaction, we can see that 2 moles of A produce 3 moles of B with an 80% yield.

### Step 2: Calculate the effective moles of B produced from A
To find out how many moles of A are needed to produce a certain amount of B, we first need to determine how many moles of B we can produce from 2 moles of A at 80% yield.

The theoretical yield of B from 2 moles of A is 3 moles. However, due to the 80% yield:
\[ \text{Effective moles of B} = \text{Theoretical moles of B} \times \text{Yield} \]
\[ = 3 \times \frac{80}{100} = 2.4 \text{ moles of B} \]

### Step 3: Understand the second reaction
The second reaction is:
\[ 2B \overset{50\%}{\rightarrow} 5D + E \]

From this reaction, 2 moles of B produce 5 moles of D with a 50% yield.

### Step 4: Calculate the effective moles of D produced from B
Now, we need to find out how many moles of D can be produced from the effective moles of B (2.4 moles):
\[ \text{Theoretical moles of D} = \text{Effective moles of B} \times \frac{5}{2} \]
\[ = 2.4 \times \frac{5}{2} = 6 \text{ moles of D} \]

Now, considering the 50% yield:
\[ \text{Effective moles of D} = 6 \times \frac{50}{100} = 3 \text{ moles of D} \]

### Step 5: Determine how many moles of A are needed for 1.5 moles of D
Now we need to find out how many moles of A are required to produce 1.5 moles of D. Since we can produce 3 moles of D from 2.4 moles of B, we can set up a ratio:
If 3 moles of D are produced from 2.4 moles of B, then:
\[ \text{Moles of B needed for 1.5 moles of D} = \frac{1.5}{3} \times 2.4 = 1.2 \text{ moles of B} \]

### Step 6: Calculate moles of A needed for 1.2 moles of B
Now we need to find out how many moles of A are needed to produce 1.2 moles of B. From the first reaction, we know that:
\[ 2 \text{ moles of A} \rightarrow 2.4 \text{ moles of B} \]

Using a ratio:
If 2 moles of A produce 2.4 moles of B, then:
\[ \text{Moles of A needed for 1.2 moles of B} = \frac{1.2}{2.4} \times 2 = 1 \text{ mole of A} \]

### Final Answer
Thus, the moles of A needed for the formation of 1.5 moles of D is:
\[ \boxed{1} \]