(i) Calculate the number of electrons which will together weigh one gram.
(ii) Calculate the mass and charge of one mole of electrons.
(i) Mass of an electron = 9.1 x 10-28 g
Or
9.1 x 10-28 g contains = 1 electron
Therefore 1g contains = 1/9.1 x 10-28 *1 = 1.098 x 1027 electrons
(ii) We know, one mole of electron = 6.022 x 1023 electron
Mass of one electron = 9.1 × 10–28 g
Or
mass of 6.022 x 1023 electron = 9.1 x 10-28 x 6.022 x 1023 = 5.48 x 10-4 g
Charge on one electron = 1.6 × 10–19 coulomb
Charge on one mole of electron = (1.6 × 10–19 C x 6.022 × 1023)
= 9.63 × 104 C
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 wavelength of an electron moving with a velocity of 2.05 × 107 ms–1.
Using s, p, d notations, describe the orbital with the following quantum numbers.
(a) n = 1, l = 0;
(b) n = 3; l =1
(c) n = 4; l = 2;
(d) n = 4; l =3.
Which of the following are isoelectronic species i.e., those having the same number of electrons?
Na+, K+, Mg2+, Ca2+, S2–, Ar
Calculate the wavelength, frequency and wave number of a light wave whose period is 2.0 × 10–10 s.
How many electrons in an atom may have the following quantum numbers?
(a) n = 4,
(b) n = 3, l = 0
Yellow light emitted from a sodium lamp has a wavelength (λ) of 580 nm. Calculate the frequency (ν) and wave number () of the yellow light.
Indicate the number of unpaired electrons in: (a) P, (b) Si, (c) Cr, (d) Fe and (e) Kr.
Calculate the wave number for the longest wavelength transition in the Balmer series of atomic hydrogen.
A photon of wavelength 4 × 10–7 m strikes on metal surface, the work function of the metal being 2.13 eV. Calculate
(i) the energy of the photon (eV),
(ii) the kinetic energy of the emission, and
(iii) the velocity of the photoelectron (1 eV= 1.6020 × 10–19 J).
How do you account for the formation of ethane during chlorination of methane?
What are hybridisation states of each carbon atom in the following compounds ?
(i) CH2=C=O,
(ii) CH3CH=CH2,
(iii) (CH3)2CO,
(iv) CH2=CHCN,
(v) C6H6
What will be the minimum pressure required to compress 500 dm3 of air at 1 bar to 200 dm3 at 30°C?
What are the common physical and chemical features of alkali metals?
Calculate the molecular mass of the following:
(i) H2O
(ii) CO2
(iii) CH4
Assign oxidation number to the underlined elements in each of the following species:
(a) NaH2PO4
(b) NaHSO4
(c) H4P2O7
(d) K2MnO4
(e) CaO2
(f) NaBH4
(g) H2S2O7
(h) KAl(SO4)2.12 H2O
What is the basic theme of organisation in the periodic table?
Explain the formation of a chemical bond.
Choose the correct answer. A thermodynamic state function is a quantity
(i) used to determine heat changes
(ii) whose value is independent of path
(iii) used to determine pressure volume work
(iv) whose value depends on temperature only.
A liquid is in equilibrium with its vapour in a sealed container at a fixed temperature. The volume of the container is suddenly increased.
a) What is the initial effect of the change on vapour pressure?
b) How do rates of evaporation and condensation change initially?
c) What happens when equilibrium is restored finally and what will be the final vapour pressure?
How would you explain the lower atomic radius of Ga as compared to Al?
How is excessive content of CO2 responsible for global warming?
How can the production of dihydrogen, obtained from ‘coal gasification’, be increased?
Write down the products of ozonolysis of 1,2-dimethylbenzene (o-xylene). How does the result support Kekule structure for benzene?
How does H2O2 behave as a bleaching agent?
A sample of pure PCl5 was introduced into an evacuated vessel at 473 K. After equilibrium was attained, concentration of PCl5 was found to be 0.5 × 10–1 mol L–1. If value of Kc is 8.3 × 10–3, what are the concentrations of PCl3 and Cl2 at equilibrium?
PCl5 (g) ↔ PCl3 (g) + Cl2(g)
Calculate the enthalpy change for the process
CCl4(g) → C(g) + 4 Cl(g)
and calculate bond enthalpy of C – Cl in CCl4(g).
ΔvapH0(CCl4) = 30.5 kJ mol–1.
ΔfH0 (CCl4) = –135.5 kJ mol–1.
ΔaH0 (C) = 715.0 kJ mol–1 , where ΔaH0 is enthalpy of atomisation
ΔaH0 (Cl2) = 242 kJ mol–1
Classify the following species into Lewis acids and Lewis bases and show how these act as Lewis acid/base:
(a) OH–
(b) F–
(c) H+
(d) BCl3
Use the periodic table to answer the following questions.
(a) Identify an element with five electrons in the outer subshell.
(b) Identify an element that would tend to lose two electrons.
(c) Identify an element that would tend to gain two electrons.
(d) Identify the group having metal, non-metal, liquid as well as gas at the room temperature.
What is smog? How is classical smog different from photochemical smog?
Thanks...
Thanks for the solution
Mass of e is 9.1 x 10^31 kg
Mr/Mrs cha,it's not necessary to take the mass of electron in kg only. We know that the mass of electron is 9.1*10^-28g or 9.1*10^-31kg so the solved question is right
Super
Mass of electron should be in kg
Mass of a electron is wrong here.It should be 9.1x 10^-31
Thnks alot
ððð
But mass of electron is 9.1 Ã10(-34)