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3 years ago

Which equation shows how wavelength is related to velocity and frequency?

Chemistry

1 answer:

Nataly_w [17]3 years ago

4 0

Answer:

The correct option is the option;

$\lambda = \dfrac{v}{f}$

Explanation:

The wavelength of a wave is the distance between two successive crests of the wave

Therefore, the wavelength, λ, is given by the fraction of the velocity, <em>v</em>, of the wave divided by the frequency, <em>f</em>, (the number of cycles that pass through a point) of the wave

Mathematically, we have;

$The \ wavelength, \ \lambda = \dfrac{The \ wave \ velocity, \ v}{The \ wave \ frequency, \ f}$

$\lambda = \dfrac{v}{f}$

You might be interested in

Zinc dissolves in hydrochloric acid to yield hydrogen gas: Zn(s) + 2HCl(aq) --> ZnCl2(aq) + H2(g) When a 12.7 g chunk of zinc

ollegr [7]

Answer:

$\boxed{\text{0.673 mol/L}}$

Explanation:

We are given the amounts of two reactants, so this is a limiting reactant problem.

1. Data:

We know we will need an equation with masses and molar masses, so let’s gather all the information in one place.

M_r: 65.38

Zn + 2HCl ⟶ ZnCl₂ + H₂

m/g: 12.7

V/mL: 5.00×10²

c/mol·L⁻¹: 1.450

2. Moles of each reactant

(a) Moles of Zn

$n = \text{12.7 g Zn} \times \dfrac{\text{1 mol Zn}}{\text{65.38 g Zn}} = \text{0.1942 mol Zn}$

(b) Moles of HCl

V = 5.0× 10² mL = 0.5000 L

$n = \text{0.5000 L HCl}\times \dfrac{\text{1.450 mol HCl}}{\text{1 L HCl}} = \text{0.7250 mol HCl}$

3. Identify the limiting reactant

Calculate the moles of ZnCl₂ obtained from each reactant

(i) From Zn

The molar ratio is 1 mol ZnCl₂:1 mol Zn

$n = \text{0.1942 mol Zn} \times \dfrac{\text{1 mol ZnCl}_{2}}{\text{1 mol Zn}} = \text{0.1942 mol ZnCl}_{2}$

(ii) From HCl

The molar ratio is 1 mol ZnCl₂:2 mol HCl

$n = \text{0.7250 mol HCl} \times \dfrac{\text{1 mol ZnCl}_{2}}{\text{2 mol HCl}} = \text{0.3625 mol ZnCl}_{2}$

Zinc is the limiting reactant, because it produces fewer moles of ZnCl₂.

4. Moles of HCl reacted

The molar ratio is 2 mol HCl:1 mol Zn

$n = \text{0.1942 mol Zn} \times \dfrac{\text{2 mol HCl}}{\text{1 mol Zn}} = \boxed{\text{0.3885 mol HCl}}$

5. Moles of HCl remaining

n = 0.7250 - 0.3885 = 0.3365 mol HCl

6. Concentration of hydrogen ions

The HCl is completely dissociated.

$c = \dfrac{\text{0.3365 mol}}{\text{0.5000 L}} = \textbf{0.673 mol/L}\\\\\text{The concentration of hydrogen ions is $\boxed{\textbf{0.673 mol/L}}$}$

4 0

3 years ago

How the solute absorb temperature from the surroundings?

Lady bird [3.3K]

The system will adjust to this increase in the heat by promoting the dissolution reaction to absorb some of the heat energy

6 0

3 years ago

Which of the following is not an amphoteric substance?

snow_lady [41]

Sắt oxit

Explanation:

7 0

2 years ago

You must make 1 L of 0.2 M acetic acid (CH3COOH). All you have available is concentrated glacial acetic acid (assay value, 98%;

Sergeu [11.5K]

Answer:

The correct answer is "11.44 ml".

Explanation:

Molarity,

= 0.2 M

Density,

= 1.05 g/ml

Volume,

= 1 L

As we know,

⇒ $Molarity=\frac{No. \ of \ moles }{Volume \ of \ solution}$

or,

⇒ $No. \ of \ moles=Molarity\times Volume$

On putting the values, we get

⇒ $=0.2\times 1$

⇒ $=0.2 \ moles$

Now,

⇒ $No. \ of \ moles=\frac{Mass \ taken}{Molecular \ mass}$

or,

⇒ $Mass \ taken=No. \ of \ moles\times Molecular \ mass$

⇒ $=0.2\times 60.05$

⇒ $=12.01 \ gram$

hence,

⇒ $Density= \frac{Mass }{Volume}$

or,

⇒ $Volume=\frac{Mass}{Density}$

⇒ $=\frac{12.01}{1.05}$

⇒ $=11.44 \ ml$

7 0

3 years ago

Which of the following must be true about a reaction if it is only spontaneous at high temperatures?

Anastaziya [24]

1) Answer is: It is endothermic, with both positive enthalpy and entropy changes.

Endothermic reactions (ΔH>0) that increase the entropy of the system (ΔS>0) are spontaneous at high temperatures.

The change in Gibbs free energy (ΔG), at constant temperature and pressure, is: ΔG=ΔH−TΔS.

ΔH is the change in enthalpy.

ΔS is change in entropy.

T is temperature of the system.

When ΔG is negative, a reaction (occurs without the addition of external energy) will be spontaneous (exergonic).

2) Answer is: It is endothermic and heat is added to the system.

There are two types of reaction:

1) endothermic reaction (chemical reaction that absorbs more energy than it releases, ΔH>0).

2) exothermic reaction (chemical reaction that releases more energy than it absorbs).

For example, the breakdown of ozone is an endothermic process. Ozone has lower energy than molecular oxygen (O₂) and oxygen atom, so ozone need energy to break bond between oxygen atoms.

3) Answer is: For every two AB produced, the reaction requires three A.

Balanced chemical reaction: 3A + B → 2AB.

From balanced chemical reaction: n(A) : n(AB) = 3 : 2.

n(A) = 3 · n(AB) ÷ 2.

A and B are reactants and AB is product of balanced chemical reaction.

For every two AB produced, the reaction requires one B.

4) Answer is:

the amount of required activation energy = potential energy of the B - potential energy of the reactants A.

the enthalpy change of the reaction = potential energy of the products C - potential energy of the reactants A.

For all chemical reaction some energy is required and that energy is called activation energy (energy that needs to be absorbed for a chemical reaction to start).

This is endothermic reaction.

3 0

3 years ago