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4 years ago

Identify and explain exothermic and endothermic reactions in terms of energy transfer

1 answer:

5 0

Exothermic reaction is when the system releases energy to the surrounding, the energy (in the perspective of the system) will have a sign of negative, as the system is transferring energy towards the surrounding.

Endothermic reaction is when the system is absorbing energy from the surrounding, the energy (in the perspective of the system) will have a sign of positive, as energy is transferred to the system.

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Benzoyl chloride, C6H5COCl, reacts with water to form benzoic acid, C6H5COOH, and hydrochloric acid. This first-order reaction i

djyliett [7]

<u>Answer:</u> The time required for the conversion of benzoyl chloride to benzoic acid is 390 seconds.

<u>Explanation:</u>

The expression for the rate law of first order kinetics is given as:

$\ln \frac{N}{N_o}=e^{-kt}$ ......(1)

where,

$N_o$ = initial mass of isotope = 100 g

N = mass of the parent isotope left after the time = 100 - 25 = 75 g

t = time taken = 26 s

k = rate constant = ?

Putting values in above equation, we get:

$\ln \frac{75}{100}=e^{-k\times 26}\\\\k=0.011065s^{-1}$

Now, we need to find the time when 99 % of the reaction is complete. Using equation 1 again, we get:

$N_o$ = initial mass of isotope = 100 g

N = mass of the parent isotope left after the time = 100 - 99 = 1 g

t = time taken = ? s

k = rate constant = $0.011065s^{-1}$

Putting values in above equation, we get:

$\ln \frac{1}{100}=e^{-0.011065\times t}\\\\t=416s$

Time required for the conversion of benzoyl chloride to benzoic acid = 416 - 26 = 390 s

8 0

3 years ago

Scientific paper is rejected during peer review of a journal because the

Alona [7]

I answered C and i was correct

6 0

3 years ago

If 1.332 mol of C4H10 are reacted with 6.504 mol of O2, how many mol of the excess reagent will remain unreacted? 2 C4H10 + 13 O

Luden [163]

Answer: The number of moles of excess reagent remain unreacted will be, 6.004 moles.

Explanation : Given,

Moles of $C_4H_{10}$ = 1.332 mol

Mass of $O_2$ = 6.504 mol

First we have to calculate the limiting and excess reagent.

The balanced chemical equation is:

$C_4H_{10}+13O_2\rightarrow 10H_2O+8CO_2$

From the balanced reaction we conclude that

As, 13 mole of $O_2$ react with 1 mole of $C_4H_{10}$

So, 6.504 moles of $O_2$ react with $\frac{6.504}{13}=0.5003$ moles of $C_4H_{10}$

From this we conclude that, $C_4H_{10}$ is an excess reagent because the given moles are greater than the required moles and $O_2$ is a limiting reagent and it limits the formation of product.

Number of moles remain unreacted = 6.504 mol - 0.5003 mol = 6.004 mol

Therefore, the number of moles of excess reagent remain unreacted will be, 6.004 moles.

5 0

3 years ago

Why you cannot add 0.3 moles of calcium fluoride directly to 1L of water to make a 0.3 M

Semenov [28]

Answer:

Because it's not soluble in water, need to be heated acidic solution

Explanation:

Calcium Fluoride Formula: CaF2 Comprises of Ca2+ and F−

H2O = Water H+ O2- OH-

Insoluble in water

In order to dissolve a salt, you have to break apart the ions and hydrate them via a solvent.

Need to read

HSAB concept( Pearson acid-base concept) is an initialism for "hard and soft (Lewis) acids and bases"

So F- is a Halogen which is a Hard Base

And OH- is a Hard base as well

And H- is a soft base

So soft acids react best with soft bases and hard acids react best with hard bases.

Bases don't react with other bases.

4 0

3 years ago

How is the prcent of ethylene glycol in de-icing fluid related

kvv77 [185]

Sorry i have no idea

5 0

3 years ago