Chemistry, 21.07.2019 23:00 trinidymwilga

In a future hydrogen-fuel economy, the cheapest source of h2 will certainly be water. it takes 467 kj to produce 1 mol of h atoms from water. what is the frequency, wavelength, and minimum energy of a photon that can free an h atom from water? enter your answers in scientific notation.

Answers: 1

Show answers

Answers

1 mol ≡ 6.023 x 10^23 molecules are produced using 467000 j of energy,
then production of 1 molecule will required energy = $\frac{467000}{6.023X10^2^3}$ = 7.7536 x 10^(-19) j

Thus, mininum energy of a photon that can free a H-atom from water is 7.7536 x 10^(-19) j.

Now, we know that E = hv
where, h = planck's constant = 6.63 10^(34) J.s
v = frequency of photon
∴ v = $\frac{E}{h}$ = $\frac{7.7536 X 10^(^-^1^9^)}{6.63X10^(^-^3^4^)}$ = 1.1702 X 10^(15) Hz

We also know that, wavelength (∧) = $\frac{c}{v}$
= $\frac{3X10^8}{1.1702X10^(^1^5^)}$
= 2.56 X 10^(-7) m

Answer from: hahahwha

The minimum energy of a photon that can produce one hydrogen atom from water is $\boxed{7.755 \times {{10}^{ - 19}}{\text{ J}}}$

The frequency of the photon is $\boxed{1.17 \times {{10}^{15}}{\text{ }}{{\text{s}}^{ - 1}}}$ .

The wavelength of the photon is $\boxed{2.563 \times {{10}^{ - 7}}{\text{ m}}}$ .

Further Explanation:

Frequency $\left( \nu \right)$ is defined as number of times n event occurs in unit time. It is generally applied to waves including light, sound, and radio waves. It is denoted by ${\nu }}$ and its SI unit is Hertz (Hz).

Wavelength is the characteristic property of a wave. It is defined as the distance between two successive crests or troughs. A crest is that point where there is maximum displacement of the medium whereas trough is a point that has minimum displacement of the medium. It is represented by $\lambda$ and its SI unit is meter (m).

First, the energy required to produce one hydrogen atom in joule can be calculated as follows:

$E\left({\text{J}}\right)=\frac{{E\left( {{\text{kJ}}}\right)\times\left({\frac{{{{10}^3}{\text{ J}}}}{{{\text{kJ}}}}}\right)}}{{{{\text{N}}_{\text{A}}}}}$ …… (1)

Here, ${{\text{N}}_{\text{A}}}$ is an Avogadro's number and has a value $6.022 \times {10^{23}}{\text{ mo}}{{\text{l}}^{ - 1}}$ .

Substitute $467{\text{ kJ/mol}}$ for $E\left( {{\text{kJ}}} \right)$ and $6.022 \times {10^{23}}{\text{ mo}}{{\text{l}}^{ - 1}}$ for ${{\text{N}}_{\text{A}}}$ in equation (1).

$\begin{aligned}E\left( {\text{J}} \right)&=\frac{{\left({467{\text{ kJ/mol}}} \right) \times \left( {\frac{{{{10}^3}{\text{ J}}}}{{{\text{kJ}}}}}\right)}}{{6.022\times {{10}^{23}}{\text{ mo}}{{\text{l}}^{-1}}}}\\&=7.755\times{10^{-19}}{\text{ J}}\\\end{aligned}$

Thus the energy of a photon that can free one atom of hydrogen is $7.755 \times {10^{ - 19}}{\text{ J}}$ .

The expression of frequency and energy is as follows:

E=hv …… (2)

Here, is a frequency of photon and h is a Plank’s constant and has a value $\left({6.626\times{{10}^{-34}}{\text{ Js}}}\right)$ .

Rearrange equation (2) to calculate the frequency of the photon as follows:

$v=\frac{E}{h}$ …… (3)

Substitute $6.626\times{10^{-34}}{\text{ J}}\cdot{\text{s}}$ for h and $7.755 \times {10^{-19}}{\text{ J}}$ for E in equation (3).

$\begin{aligned}v&=\frac{{7.755\times{{10}^{-19}}{\text{ J}}}}{{6.626\times{{10}^{-34}}{\text{ Js}}}}\\&=1.17\times{10^{15}}{\text{}}{{\text{s}}^{-1}}\\\end{aligned}$

Thus the frequency of photon is $1.17\times{10^{15}}{\text{}}{{\text{s}}^{-1}}$ .

The expression to calculate the wavelength from energy of the photon is as follows:

$E = \frac{{h{\text{c}}}}{{\lambda }}}$ …… (4)

Here ${\lambda }}$ is a wavelength of a photon and c is a speed of light.

Rearrange equation (4) to calculate wavelength of the photon as follows:

${\lambda }}=\frac{{h{\text{c}}}}{E}$ …… (5)

Substitute $6.626 \times {10^{ - 34}}{\text{ J}} \cdot {\text{s}}$ for h, $3.0 \times {10^8}{\text{ m/s}}$ for c and $7.755 \times {10^{ - 19}}{\text{ J}}$ for E in equation (5).

$\begin{aligned}{\lambda}}=\frac{{\left({6.626\times {{10}^{-34}}{\text{ J}}\cdot {\text{s}}} \right)\left( {3.0 \times {{10}^8}{\text{ m/s}}}\right)}}{{\left({7.755\times {{10}^{ - 19}}{\text{ J}}} \right)}}\\=2.563\times {10^{-7}}{\text{m}}\\\end{aligned}$

Hence wavelength of the photon is equal to $2.563 \times {10^{ - 7}}{\text{ m}}$ .

Learn more:

1. Ranking of photons according to the wavelength of transition:

2. Calculate de Broglie wavelength of golf ball:

Answer details:

Grade: Senior School

Subject: Chemistry

Chapter: Structure of atom

Keywords: Hydrogen atom, cheapest source of h2, 467 kj, 1 mol of h atom, frequency wavelength.

Answer from: Quest

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

= 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g

Answer from: Quest

i think so it’s will be b yes i believe its

Another question on Chemistry

Chemistry, 22.06.2019 07:00

Which atom or ion is the largest? a. k b. k+ c. ca d. ca2+ e. li

Answers: 1

Answer

Chemistry, 22.06.2019 09:10

How have the greenhouse gasses increased from the year 2000 to 2018

Answers: 2

Answer

Chemistry, 22.06.2019 14:20

7. in the cycle, a virus integrates its dna into the host's dna, and its dna is replicated when the host dna is replicated. a. infectious b. retroviral c. lysogenic d.lytic

Answers: 1

Answer

Chemistry, 22.06.2019 15:30

Each of the following reactions is allowed to come to equilibrium and then the volume is changed as indicated. predict the effect (shift right, shift left, or no effect) of the indicated volume change. drag the appropriate items to their respective bins.co(g) + h2o(g) < => co2(g) + h2(g) (volume is decreased) pcl3(g) + cl2(g) < => pcl5(g) (volume is increased) caco3(s)< => cao(s) + co2(g) (volume is increased)

Answers: 1

Answer

You know the right answer?

In a future hydrogen-fuel economy, the cheapest source of h2 will certainly be water. it takes 467 k...

Questions