An ion with mass number 56 contains 3 units of positive charge and 30.4% more neutrons than electrons. Assign the symbol to this ion.
Let the number of electrons present in ion ,S3+ = x
∴ Number of neutrons in it = x + 30.4% of x = 1.304 x
Since the ion is tripositive,
⇒ Number of electrons in neutral atom = x + 3
∴ Number of protons in neutral atom = x + 3
Now mass number = no of protons + no of neutrons
56 = x + 3 + 1.304x
Or 2.304x = 53
Or x = 23
Therefore no of protons = atomic no = x + 3 = 23 + 3 = 26
∴ The symbol of the ion
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;
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(d) n = 4; l =3.
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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.
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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
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(ii) the kinetic energy of the emission, and
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(i) CH2=C=O,
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(iv) CH2=CHCN,
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(iii) CH4
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(a) NaH2PO4
(b) NaHSO4
(c) H4P2O7
(d) K2MnO4
(e) CaO2
(f) NaBH4
(g) H2S2O7
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(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?
What sorts of informations can you draw from the following reaction ?
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Distinguish between a sigma and a pi bond.
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(ii) –52.27 kJ mol–1
(iii) +74.8 kJ mol–1
(iv) +52.26 kJ mol–1
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?
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Why no. of electron is x+3
An atom contains 5.6% more neutrons than protons.The atomic mass is 56.Than atomic number is?