Answer:
There are 36 grams in 4.00 moles of Carbon.
Explanation:
In order to convert from moles of a substance into grams of the same substance, we need to use the substance's molar mass.
That means that in this case we use the<em> molar mass of Carbon</em>:
- 4.00 mol * 12 g/mol = 36 g
Thus, there are 36 grams in 4.00 moles of Carbon.
1) Answer: A hot pack feels warm when chemicals in it combine.
Explanation: Reactions or process in which heat is released(produced) are known as exothermic reactions or process and those in which the heat is absorbed are known as endothermic reactions or process.
If a beaker feels cools when chemical in it react then it means the chemicals have absorbed the heat energy from its surroundings and so it is an example of an endothermic process.
A hot pack feels warm when chemicals in it combine means the energy is released in the chemical reaction and so it is an example of an exothermic process.
Plants use the sun's energy for photosynthesis which is a process of forming food for the plants. Energy acts as a reactant in this process and so it is an example of endothermic process.
Frying an egg by heating it on a stove is an example of an endothermic process as the heat is required to fry the egg.
So, the only exothermic process is the second one, "A hot pack feels warm when chemicals in it combine."
2) In the given equation, heat is written as a product means the heat is released in the equation and so it is an example of an exothermic reaction.
So, the correct choice is the last one " It is exothermic because energy is released."
Answer: 0.03798 kilograms
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number
of particles.
To calculate the moles, we use the equation:
1 mole of chlorine gas
weighs = 71 g
Thus 0.535 moles of chlorine gas
will weigh =
(1kg=1000g)
Thus there are 0.03798 kilograms in 12 L of chlorine gas.
Answer choice A is correct
<u>Answer:</u> The energy of photon is ![162.93\times 10^{-26}J](https://tex.z-dn.net/?f=162.93%5Ctimes%2010%5E%7B-26%7DJ)
<u>Explanation:</u>
The relation between energy and wavelength of light is given by Planck's equation, which is:
![E=\frac{hc}{\lambda}](https://tex.z-dn.net/?f=E%3D%5Cfrac%7Bhc%7D%7B%5Clambda%7D)
where,
E = energy of the light = ?
h = Planck's constant = ![6.626\times 10^{-34}Js](https://tex.z-dn.net/?f=6.626%5Ctimes%2010%5E%7B-34%7DJs)
c = speed of light = ![3\times 10^8m/s](https://tex.z-dn.net/?f=3%5Ctimes%2010%5E8m%2Fs)
= wavelength of photon = 0.122 m
Putting values in above equation, we get:
![E=\frac{(6.626\times 10^{-34}Js)\times (3\times 10^8m/s)}{0.122m}\\\\E=162.93\times 10^{-26}J](https://tex.z-dn.net/?f=E%3D%5Cfrac%7B%286.626%5Ctimes%2010%5E%7B-34%7DJs%29%5Ctimes%20%283%5Ctimes%2010%5E8m%2Fs%29%7D%7B0.122m%7D%5C%5C%5C%5CE%3D162.93%5Ctimes%2010%5E%7B-26%7DJ)
Hence, the energy of photon is ![162.93\times 10^{-26}J](https://tex.z-dn.net/?f=162.93%5Ctimes%2010%5E%7B-26%7DJ)