Home
NCERT Soltions
Class 11
Chemistry
Structure of Atom
Electromagnetic radiation of wavelength 242 nm is just sufficient to i...

Electromagnetic radiation of wavelength | Class 11 Chemistry Chapter Structure of Atom, Structure of Atom NCERT Solutions

Question:

Electromagnetic radiation of wavelength 242 nm is just sufficient to ionise the sodium atom. Calculate the ionisation energy of sodium in kJ mol^–1.

Answer:

From E= hv or hc/ λ, we have λ = 242nm or 242 x 10^-9m

C = 3 x 10⁸ m/s

h = 6.62 x 10^-34 Js

Now putting these values in the equation we get

E= (6.62 x 10^-34 Js x 3 x 10⁸ m/s) / (242 x 10^-9m)

= 0.0821 x 10^-17 J/atom

E = (0.0821 x 10^-17 ) / (1000 x 6.02 x 10²³)

= 494 KJ/mol

1
0
0
Report?

Report a problem on Specifications:

Email id:

Comments

Next Question >

Popular questions of class 11 Chemistry

The mass of an electron is 9.1 × 10^–31 kg. If its K.E. is 3.0 × 10^–25 J, calculate its wavelength.

Calculate the amount of carbon dioxide that could be produced when

(i) 1 mole of carbon is burnt in air.

(ii) 1 mole of carbon is burnt in 16 g of dioxygen.

(iii) 2 moles of carbon are burnt in 16 g of dioxygen.

Calculate the wavelength of an electron moving with a velocity of 2.05 × 10⁷ ms^–1.

Balance the following redox reactions by ion – electron method :

(a) MnO₄^–(aq) + I^–(aq) → MnO_{2 (s)} + I_2(s) (in basic medium)

(b) MnO₄ ^– (aq) + SO_{2 (g)}→ Mn²⁺ (aq) + HSO₄^– (aq) (in acidic solution)

(d) Cr₂O₇ ^2– + SO_2(g) → Cr³⁺ _(aq) + SO₄^2–(aq) (in acidic solution)

In a process, 701 J of heat is absorbed by a system and 394 J ofwork is done by the system. What is the change in internal energy for the process?

What will be the minimum pressure required to compress 500 dm³ of air at 1 bar to 200 dm³ at 30°C?

In a reaction A + B2 → AB2 Identify the limiting reagent, if any, in the following reaction mixtures.

(i) 300 atoms of A + 200 molecules of B

(ii) 2 mol A + 3 mol B

(iii) 100 atoms of A + 100 molecules of B

(iv) 5 mol A + 2.5 mol B

(v) 2.5 mol A + 5 mol B

At 0°C, the density of a certain oxide of a gas at 2 bar is same as that of dinitrogen at 5 bar. What is the molecular mass of the oxide?

Which one of the following will have largest number of atoms?

(i) 1 g Au (s)

(ii) 1 g Na (s)

(iii) 1 g Li (s)

(iv) 1 g of Cl2(g)

Density of a gas is found to be 5.46 g/dm³ at 27 °C at 2 bar pressure. What will be its density at STP?

Recently Viewed Questions of Class 11 Chemistry

Describe the effect of :

a) addition of H₂

b) addition of CH₃OH

c) removal of CO

d) removal of CH₃OH on the equilibrium of the reaction: 2H₂(g) + CO (g) ↔ CH₃OH (g)

Arrange the following

(i) CaH₂, BeH₂and TiH₂in order of increasing electrical conductance.

(ii) LiH, NaH and CsH in order of increasing ionic character.

(iii) H-H, D-D and F-F in order of increasing bond dissociation enthalpy.

(iv) NaH, MgH₂and H₂O in order of increasing reducing property.

The first (ΔiH1) and the second (ΔiH) ionization enthalpies (in kJ mol–1) and the (ΔegH) electron gain enthalpy (in kJ mol–1) of a few elements are given below:

Elements	Δ_iH1	Δ_iH	Δ_egH
I	520	7300	-60
II	419	3051	-48
III	1681	3374	-328
IV	1008	1846	-295
V	2372	5251	+48
VI	738	1451	-40

Which of the above elements is likely to be :

(a) the least reactive element.

(b) the most reactive metal.

(d) the least reactive non-metal.

(e) the metal which can form a stable binary halide of the formula MX₂, (X=halogen).

(f) the metal which can form a predominantly stable covalent halide of the formula MX (X=halogen)?

What will be the minimum pressure required to compress 500 dm³ of air at 1 bar to 200 dm³ at 30°C?

Determine the molecular formula of an oxide of iron in which the mass per cent of iron and oxygen are 69.9 and 30.1 respectively. Given that the molar mass of the oxide is 159.69 g mol^–1.

Balance the following redox reactions by ion – electron method :

(a) MnO₄^–(aq) + I^–(aq) → MnO_{2 (s)} + I_2(s) (in basic medium)

(b) MnO₄ ^– (aq) + SO_{2 (g)}→ Mn²⁺ (aq) + HSO₄^– (aq) (in acidic solution)

(d) Cr₂O₇ ^2– + SO_2(g) → Cr³⁺ _(aq) + SO₄^2–(aq) (in acidic solution)

2.9 g of a gas at 95 °C occupied the same volume as 0.184 g of dihydrogen at 17 °C, at the same pressure. What is the molar mass of the gas?

In a process, 701 J of heat is absorbed by a system and 394 J ofwork is done by the system. What is the change in internal energy for the process?

If the speed of light is 3.0 × 10⁸ ms^–1, calculate the distance covered by light in 2.00 ns.

How would you explain the lower atomic radius of Ga as compared to Al?

Study Tips for Answering NCERT Questions:

NCERT questions are designed to test your understanding of the concepts and theories discussed in the chapter. Here are some tips to help you answer NCERT questions effectively:

Read the question carefully and focus on the core concept being asked.
Reference examples and data from the chapter when answering questions about Structure of Atom.
Review previous year question papers to get an idea of how such questions may be framed in exams.
Practice answering questions within the time limit to improve your speed and accuracy.
Discuss your answers with your teachers or peers to get feedback and improve your understanding.

Comments

Rahmat Fatima
2020-07-14 19:34:52

Thq a lot to give this answers

Kanchan verma
2019-11-14 14:03:57

I have problem in dealing with numerical

Varnika
2019-11-12 06:52:27

Thank

Y
2019-07-01 22:29:54

Aisha
2019-05-17 11:40:28

What about if use hydrogen instead of sodium

Priyanshi
2019-04-23 20:05:25

Tq saralstudy

Aryan
2019-03-24 15:13:14

Why cant we use -13.6Z^2

Aryan
2019-03-24 15:13:02

Why cant we use -13.6Z^2

Megha
2018-11-07 18:37:49

How it's come?

Abhishek upmanyu
2018-08-23 11:13:59

Right solution

Comment(s) on this Question

Welcome to the NCERT Solutions for Class 11 Chemistry - Chapter . This page offers a step-by-step solution to the specific question from Excercise 1 , Question 10: Electromagnetic radiation of wavelength 242 nm is just sufficient to ionise the sodium atom. Calcula....

Electromagnetic radiation of wavelength | Class 11 Chemistry Chapter Structure of Atom, Structure of Atom NCERT Solutions

< Previous Question

Next Question >

Popular questions of class 11 Chemistry

Recently Viewed Questions of Class 11 Chemistry

Study Tips for Answering NCERT Questions:

Comments

Comment(s) on this Question

Chapters for Class 11 Chemistry

Subjects for Class 11

Students Also Read

Important links

Quick Links

Resources

Support