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प्रश्न
Analysis shows that nickel oxide has the formula Ni0.98O1.00. What fractions of nickel exist as Ni2+ and Ni3+ ions?
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उत्तर
The formula Ni0.98O1.00 indicates that 98 Ni atoms are associated with 100 O atoms. Suppose,
Number of Ni atoms present as Ni2+ = x
∴ Number of Ni atoms present as Ni3+ = 98 − x
Since nickel oxide is electrically neutral, the total charge present on x Ni2+ ions and (98 − x) Ni3+ ions should be equal to the total charge present on 100 O2− ions. Therefore, we have
(x × 2) + (98 − x) × 3 = 100 × 2
or 2x + 294 − 3x = 200
or x = 94
∴ Fraction of Ni present as Ni2+ = `94/98 xx 100`
= 95.9
= 96%
and fraction of Ni present as Ni3+ = `(98 - 94)/98 xx 100`
= 4.08
= 4%
संबंधित प्रश्न
What is ferromagnetism?
Define the following term:
Ferromagnetism
Write the type of magnetism observed when the magnetic moments are oppositely aligned and cancel out each other.
Explain the following with suitable examples:
Ferrimagnetism
Give reasons:Ferrimagnetic substances show better magnetism than antiferromagnetic substances.
The complexion [Ni(CN)4]2- is:
Explain why:
(i) Transition elements form coloured compounds.
(ii) Interhalogen compounds are more reactive than their constituent elements.
(iii) Cu+ is diamagnetic but Cu2+ is paramagnetic. (Z = 29)
Pyrolusite ore is _______.
What is magnetic susceptibility?
Compare dia, para and ferromagnetism.
Give the properties of dia/para/ferromagnetic materials.
Substances which are weakly repelled in magnetic field are known as ____________.
Assertion: On heating ferromagnetic or ferrimagnetic substances, they become paramagnetic.
Reason: The electrons change their spin on heating.
Fe3O4 (magnetite) is an example of ___________.
Which of the following arrangements shows schematic alignment of magnetic moments of antiferromagnetic substances?
Which of the following statements is not true?
The value of magnetic moment is zero in the case of antiferromagnetic substances because the domains:
(i) get oriented in the direction of the applied magnetic field.
(ii) get oriented opposite to the direction of the applied magnetic field.
(iii) are oppositely oriented with respect to each other without the application of magnetic field.
(iv) cancel out each other’s magnetic moment.
Which of the following statements are correct?
(i) Ferrimagnetic substances lose ferrimagnetism on heating and become paramagnetic.
(ii) Ferrimagnetic substances do not lose ferrimagnetism on heating and remain ferrimagnetic.
(iii) Antiferromagnetic substances have domain structures similar to ferromagnetic substances and their magnetic moments are not cancelled by each other.
(iv) In ferromagnetic substances all the domains get oriented in the direction of magnetic field and remain as such even after removing magnetic field.
Which of the following is not a ferroelectric compound?
Which of the following is not paramagnetic?
Match items of List - I with those of List - II:
| List - I | List - II | ||
| (Property) | (Example) | ||
| (A) | Diamagnetism | (i) | MnO |
| (B) | Ferrimagnetism | (ii) | O2 |
| (C) | Paramagnetism | (iii) | NaCl |
| (D) | Antiferromagnetism | (iv) | Fe3O4 |
Choose the most appropriate answer from the options given below:
Give a reason for the following:
Cu+2 salts are paramagnetic, while Cu+ salts are diamagnetic.
The metal complex ion that is paramagnetic is ______.
(Atomic number of Fe = 26, Cu = 29, Co = 27 and Ni = 28)
