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3 years ago

Can anyone help me with the calculations for the Frequency, Wavelength, Energy Chart?

Chemistry

1 answer:

sergeinik [125]3 years ago

3 0

Use the following equations to fill the chart.

E = hf
where
h = 6.63 x 10⁻³⁴ J/s, Planck's constant
f = frequency Hz
E = quanta of energy, J

c = fλ
where
c = 3 x 10⁸ m/s, the velocity of light
λ = wavelength, m

If energy is given in J/mmol, divide by Avogadro's number, N = 6.02 x 10²³, to convert it to J.

The completed table is shown below.

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90 POINTSSSS!!!

Katarina [22]

Answer:

$\large \boxed{\text{-2043.96 kJ/mol}}$

Explanation:

Assume the reaction is the combustion of propane.

Word equation: propane plus oxygen produces carbon dioxide and water

Chemical eqn: C₃H₈(g) + O₂(g) ⟶ CO₂(g) + H₂O(g)

Balanced eqn: C₃H₈(g) + 5O₂(g) ⟶ 3CO₂(g) + 4H₂O(g)

(a) Table of enthalpies of formation of reactants and products

$\begin{array}{cc}\textbf{Substance} & \textbf{$\Delta_{\text{f}}$H/(kJ/mol}) \\\text{C$_{3}$H$_{8}$(g)} & -103.85 \\\text{O}_{2}\text{(g)} & 0 \\\text{CO}_{2}\text{(g)} & -393.51 \\\text{H$_{2}$O(g)} & -241.82\\\end{array}$

(b)Total enthalpies of reactants and products

$\Delta_{\text{rxn}}H^{\circ} = \sum \left( \Delta_{\text{f}} H^{\circ} \text{products}\right) - \sum \left (\Delta_{\text{f}}H^{\circ} \text{reactants} \right)\\= \text{-2147.81 kJ/mol - (-103.85 kJ/mol)}\\= \text{-2147.81 kJ/mol + 103.85 kJ/mol}\\= \textbf{-2043.96 kJ/mol}\\\text{The enthalpy change is $\large \boxed{\textbf{-2043.96 kJ/mol}}$}$

ΔᵣH° is negative, so the reaction is exothermic.

5 0

2 years ago

Help can you match the answers to the definition PLZ Need this ASAP 30 points

Alchen [17]

Answer:

1-C

2-D

3-B

4-A

Explanation:

I think it is this if it is not , sorry!

8 0

3 years ago

Selenium (Se) has 30 protons and 20 neutrons in each atom, therefore its atomic

allochka39001 [22]

Answer:

30, 50

Explanation:

Hello,

In this since an element's atomic number is equal to the number of protons in its atom, we can infer that selenium's atomic number is 30. Moreover, due to the fact the the neutrons are equal to the atomic mass minus the atomic number or the number of protons, by knowing the number of neutrons we compute the atomic as follows:

$neutrons=mass-protons\\\\mass=neutrons+protons\\\\mass=30+20\\\\mass=50a.m.u$

Thus, answer is 30, 50.

Best regards.

8 0

3 years ago

What phenomenon in nature do scientists use to define the length of a meter? Why is this a better definition than “the length of

sergey [27]

Answer:

The natural phenomenon used to describe the length of a meter is the speed of light. The length of a meter is the length a light path travels in 1/(299792458) seconds through a vacuum.

The definition is better due to the uncertainty involved in the use of the length of a standard meter stick because the length of the meter stick could change due to atmospheric conditions from place to place

Explanation:

8 0

3 years ago

Sometimes you are given a measured amount of two or more reactants and asked how much product can be formed. Explain what steps

Westkost [7]

Explanation:

To solve this problem, follow these steps;

Obtain a balanced equation of the reaction and familiarize with the reactants and products.
Find the number of moles of the reacting species since they are the known matter in terms of quantity.
From the number of moles, determine the limiting reactant.
The limiting reactant is the one given in short supply.
Such reactant determines the extent of the reaction.
Compare the moles of this specie to that of the products using the balanced equation.
Obtain the mole of the desired product and find the mass or desired quantity.
simply work from the known specie to the unknown

learn more:

Number of moles brainly.com/question/13064292

#learnwithBrainly

4 0

3 years ago