Which of the following is an example of organic insecticides? a) Aldrin b) Lead arsenate c) Lime sulphur d) Fluorides

Rus_ich [418]

Answer:

$\Delta\text{H}_1+2\Delta\text{H}_2-\Delta\text{H}_3$

Explanation:

Hess's Law of Constant Heat Summation states that if a chemical equation can be written as the sum of several other chemical equations, the enthalpy change of the first chemical equation is equal to the sum of the enthalpy changes of the other chemical equations. Thus, the reaction that involves the conversion of reactant A to B, for example, has the same enthalpy change even if you convert A to C, before converting it to B. Regardless of how many steps it takes for the reactant to be converted to the product, the enthalpy change of the overall reaction is constant.

With Hess's Law in mind, let's see how A can be converted to 2C +E.

$\bf{\text{A} \rightarrow 2\text{B}}$ (Δ $\text{H}_1$ ) -----(1)

Since we have 2B, multiply the whole of II. by 2:

$\bf{2\text{B} \rightarrow 2\text{C} +2\text{D}}$ (2Δ $\text{H}_2$ ) -----(2)

This step converts all the B intermediates to 2C +2D. This means that the overall reaction at this stage is $\text{A} \rightarrow 2\text{C} +2\text{D}$ .

Reversing III. gives us a negative enthalpy change as such:

$\bf{2\text{D} \rightarrow \text{E}}$ (-Δ $\text{H}_3$ ) -----(3)

This step converts all the D intermediates formed from step (2) to E. This results in the overall equation of $\text{A} \rightarrow 2\text{C} +\text{E}$ , which is also the equation of interest.

Adding all three together:

$\text{A} \rightarrow 2\text{C}+\text{E}$ ( $\bf{\Delta\text{H}_1+2\Delta\text{H}_2-\Delta\text{H}_3 }$ )

Thus, the first option is the correct answer.

Supplementary:

To learn more about Hess's Law, do check out: brainly.com/question/26491956

4 0

1 year ago

Element A has a half-life of 10 days. A scientist measures out 200 g of this substance. After 30 days has passed, the scientist

myrzilka [38]

N=N₀*2^(-t/T)

N₀=200 g
T=10 d
t=30 d

N=200*2^(-30/10)=25 g

25 g will remain

4 0

3 years ago

Read 2 more answers

Honestly reporting experimental findings is an example of using good

GaryK [48]

I would say that honestly reporting experimental findings is an example of using good science because science is definitely about honesty in accepting experimental findings and realizing that one has to face up to the consequences and develop things from there rather than wishing the outcome was different.

4 0

2 years ago

Why are carbon dioxide concentrations expected to increase?

makvit [3.9K]

Carbon dioxide concentrations expected to increase because fossil fuel burning is expected to increase

3 0

3 years ago

Read 2 more answers

Calculate the percent composition for each of the elements in Na3PO4. A 5.00 gram sample of an oxide of lead PbxOy contains 4.33

Shkiper50 [21]

Answer:

1. Percentage composition of: Na = 42%; P = 19.0%; O = 39%

2. Simplest formula of compound is PbO₂

3. (i) 2Cu(NO₃) ---> 2CuO + 2NO₂ + 3O₂

(ii) 2C₂H₆ + 7O₂ ---> 4CO₂ + 6H₂O

(iii) Mg₃N₂ + 6H₂O ---> 3Mg(OH)₂ + 2NH₃

4. 48 g of MG will react with 2 moles of Cl₂

5. 0.288 g of SO2 will be produced from the combustion of 0.331 g P₄S₃ in excess O₂

6. 12.8 g of nitric oxide can be produced from the reaction of 8.00 g NH₃ with 17.0 g O₂

7. The stock acid solution should be diluted to 6000 mL or 6.0 L

Explanation:

The full explanation is found in the attachments below

6 0

3 years ago

Which of the following is an example of organic insecticides? a) Aldrin b) Lead arsenate c) Lime sulphur d) Fluorides​

Which of the following is an example of organic insecticides? a) Aldrin b) Lead arsenate c) Lime sulphur d) Fluorides