Answer : The standard enthalpy of formation of ethylene is, 51.8 kJ/mole
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The formation reaction of 
will be,
The intermediate balanced chemical reaction will be,
(1) 
(2) 
(3) 
Now we will reverse the reaction 1, multiply reaction 2 and 3 by 2 then adding all the equations, we get :
(1) 
(2) 
(3) 
The expression for enthalpy of formation of will be,
Therefore, the standard enthalpy of formation of ethylene is, 51.8 kJ/mole
I believe the answer would be A. A pea is to a pod
Answer:
The gas argon does not reach a state of vibrational excitation when infrared radiation strikes this gas.
Explanation:
The dry atmosphere is composed almost entirely of nitrogen (in a volumetric mixing ratio of 78.1%) and oxygen (20.9%), plus a series of oligogases such as argon (0.93%), helium and gases of greenhouse effect such as carbon dioxide (0.035%) and ozone. In addition, the atmosphere contains water vapor in very variable amounts (about 1%) and aerosols.
Greenhouse gases or greenhouse gases are the gaseous components of the atmosphere, both natural and anthropogenic, that absorb and emit radiation at certain wavelengths of the infrared radiation spectrum emitted by the Earth's surface, the atmosphere and clouds . In the Earth's atmosphere, the main greenhouse gases (GHG) are water vapor (H2O), carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4) and ozone (O3 ). There is also in the atmosphere a series of greenhouse gases (GHG) created entirely by humans, such as halocarbons (compounds containing chlorine, bromine or fluorine and carbon, these compounds can act as potent greenhouse gases in the atmosphere and they are also one of the causes of the depletion of the ozone layer in the atmosphere) regulated by the Montreal Protocol. In addition to CO2, N2O and CH4, the Kyoto Protocol sets standards regarding sulfur hexafluoride (SF6), hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs).
The difference between argon and greenhouse gases such as CO2 is that the individual atoms in the argon do not have free bonds and therefore do not vibrate. As a consequence, it does not reach a state of vibrational excitation when infrared radiation strikes this gas.
Answer:
Explanation:
Hello there!
In this case, according to the given question about stoichiometry, it is possible for us to calculate the required moles of water that will be produced by 12 grams of hydrogen, by using the molar mass of this reactant (2.02 g/mol as it is diatomic) and the 2:2 mole ratio in the chemical equation by solving the following setup:
Regards!
The sample with the lowest AVERAGE kinetic energy is
the coolest one.
The sample with the lowest TOTAL kinetic energy depends on
not only the temperature of the samples, but also on their size,
since each molecule in the sample has kinetic energy.
