Neon gas is generally used in the sign boards. If it emits strongly at 616 nm, calculate
(a) the frequency of emission,
(b) distance traveled by this radiation in 30 s
(c) energy of quantum and
(d) number of quanta present if it produces 2 J of energy.
λ = 616nm or = 616x10-9m
a) Frequency , v=c/ λ = 3.8x108 / 616x10-9 = 4.87x1014 s-1
b) Velocity of the radiation = 3x108 m/s
Therefore distance travelled in 30s = 30x3x108 = 9.0x109m
c) E = hv = hc/ λ = (6.626x10-34)(3.0x108) / (616x10-9 ) = 32.27x10-20J
d) No of quanta in 2J of energy = 2/32.27 x 10-28 = 6.2x1018
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) → MnO2 (s) + I2(s) (in basic medium)
(b) MnO4 – (aq) + SO2 (g) → Mn2+ (aq) + HSO4– (aq) (in acidic solution)
(c) H2O2 (aq) + Fe 2+ (aq) → Fe3+ (aq) + H2O (l) (in acidic solution)
(d) Cr2O7 2– + SO2(g) → Cr3+ (aq) + SO42– (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?
Determine the empirical formula of an oxide of iron which has 69.9% iron and 30.1% dioxygen by mass.
A reaction, A + B → C + D + q is found to have a positive entropy change. The reaction will be
(i) possible at high temperature
(ii) possible only at low temperature
(iii) not possible at any temperature
(iv) possible at any temperature
Knowing the properties of H2O and D2O, do you think that D2O can be used for drinking purposes?
The increasing order of reactivity among group 1 elements is Li < Na < K < Rb CI > Br > I. Explain.
Write Lewis dot symbols for atoms of the following elements: Mg, Na, B, O, N, Br.
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?
Arrange the following set of compounds in order of their decreasing relative reactivity with an electrophile, E+
(a) Chlorobenzene, 2,4-dinitrochlorobenzene, p-nitrochlorobenzene
(b) Toluene, p-H3C-C6H4-NO2, p-O2N-C6H4-NO2.
How would you explain the lower atomic radius of Ga as compared to Al?
How can saline hydrides remove traces of water from organic compounds?
How do you express the bond strength in terms of bond order?
C = 3.0 E8 not 3.8 E8 m/s.
a) Frequency , v=c/ λ = 3.8x108 / 616x10-9 = 4.87x1014 s-1 I got 6.17E14 1/s
Thqs for this answers
Thank you to S²
Thanks for answering me
Velocity of radiation ko velocity of light kyo liya
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Can you explain option (d) in detail
Nice
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