When looking down the groups the elements have an equal number of electrons in the outer shell. This means they react in a similar way making it easier for scientists to use.
Answer:
The energy of electromagnetic radiation increases as its frequency increases.
The frequency and wavelength of electromagnetic radiation are inversely proportional.
Explanation:
According to Max Plank's equation, the energy of electromagnetic radiation is given by E=hf where h= Plank's constant and f= frequency of the electromagnetic radiation. This means that the energy and frequency of electromagnetic radiation and its energy are related by a direct proportion. As frequency of the electromagnetic radiation increases, the energy of the radiation increases also.
However, frequency and wavelength of electromagnetic radiation are inversely related. The frequency decreases with increasing wavelength of electromagnetic radiation.
Answer:
ΔH for the the reaction NO(g) + O(g) ⇒ NO₂(g) is ΔH= -304.1 kJ
Explanation:
<u>The complete question is:</u>
Consider the chemical equations shown here.
NO(g) + O₃(g) ⇒ NO₂(g) + O₂(g) (ΔH= -198.9 kJ
)
1.5 O₂(g) ⇒ O₃(g) (ΔH= 142.3 kJ
)
O(g) ⇒ 0.5 O₂(g) (ΔH= -247.5 kJ)
What is ΔH for the reaction shown below?
NO(g) + O(g) ⇒ NO₂(g)
Solution:
We have to use the Hess's Law: if a series of reagents react to give a series of products, the heat of reaction released or absorbed is independent of whether the reaction is carried out in one, two or more stages. That means enthalpy changes are additive.
NO(g)+ O₃(g) ⇒ NO₂(g) + O₂(g) (ΔH₁= -198.9 kJ
)
+
1.5 O₂(g) ⇒ O₃(g) (ΔH₂= 142.3 kJ
)
+
O(g) ⇒ 0.5 O₂(g) (ΔH₃= -247.5 kJ)
=
NO(g) + O₃(g) + 1.5 O₂(g) + O(g) ⇒ NO₂(g) + O₂(g) + O₃(g) + 0.5 O₂(g)
We remove the compounds that are in both members of the reaction:
NO(g) + O(g) ⇒ NO₂(g)
We only have to add the reactions so we add the value of each enthalpy change.
ΔH for the the reaction is given by:
ΔH= ΔH₁ + ΔH₂ + ΔH₃= -198.9 kJ +142.3 kJ -247.5 kJ= -304.1 kJ
Answer: The correct answer is true.
Explanation:
There are two types of reactions based on the heat absorbed or released:
1. Exothermic reactions: In these reactions, heat is released. The energy of the products is less than the energy of the reactants. The for these reactions is negative.
2. Endothermic reactions: In these reactions, heat is absorbed by the reactants. The energy of the products is more than the energy of the reactants. The for these reactions is positive.
In the given equation:
The energy is written on the product side, which means that the heat is released in the reaction. Hence, the given equation is a exothermic reaction.
Therefore, the given statement is true.