Answer:When a substance undergoes a chemical change some of the chemical changes can be reversed with a chemical change.
Explanation:
A chemical change changes all of the element but some chemical changes but very few can be changed back to its original substance only with a chemical change.
I think the answer is mercury
N(C)=5,02·10²² atoms
calculation check:
N(C)=(1/12)*6.022*10²³=0.5018*10²³≈5.02·10²²
Explanation:
The given data is as follows.
, 
Work produced per kJ of heat extracted from hot reservoir = 0.45 kJ = Efficiency
If the device is Carnot cycle then its efficiency will be maximum and its value will be equal to ![[1 - (\frac{T_{c}}{T_{h}} )]](https://tex.z-dn.net/?f=%5B1%20-%20%28%5Cfrac%7BT_%7Bc%7D%7D%7BT_%7Bh%7D%7D%20%29%5D)
Using this relation we will calculate the efficiency as follows.
Efficiency = ![[1 - (\frac{T_{c}}{T_{h}} )]](https://tex.z-dn.net/?f=%5B1%20-%20%28%5Cfrac%7BT_%7Bc%7D%7D%7BT_%7Bh%7D%7D%20%29%5D)
=
= 0.928
Hence, it means that this type of device is possible and the claim is also believable.
<u>0.549 mol</u> of citric acid are in 1.50 qt of lemon juice (d = 1.09 g/mL) that is 6.82% citric acid.
<h3>What is citric acid?</h3>
Citric acid is an organic compound with a chemical formula of
. It is a weak organic acid that is colourless. Citrus fruits naturally produce it. It is a biochemical intermediary in the citric acid cycle, which is a process that all aerobic organisms go through during metabolism.
Every year, more than two million tonnes of citric acid are produced. It is frequently employed as a chelating agent, an acidifier, and a flavouring
Citrates, which include salts, esters, and the polyatomic anion present in solution, are derivatives of citric acid. Trisodium citrate is an example of the former; triethyl citrate is an example of an ester.
Learn more about Citric acid
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