Advertisements
Advertisements
प्रश्न
Compute the difference in masses of one mole each of aluminium atoms and one mole of its ions. (Mass of an electron is 9.1×10–28 g). Which one is heavier?
उत्तर
Mass of 1 mole of aluminium atom = 27g mol−1
Al − 3e− → Al3+ (3 moles of electrons)
Mass of 3 moles of electrons
= 3 × (9.1 × 10−28) × 6.022 × 1023 g
= 0.00164g
Molar mass of Al3+ = 27 − 0.00164g mol−1
= 26.9984g mol−1
Difference = 27 – 26.9984
= 0.0016 g
1 mole of Al atoms is heavier than 1 mole of Al3+ions.
APPEARS IN
संबंधित प्रश्न
An element has an atomic number of 11 and its mass number is 23. What is the arrangement of electrons in the shells? State nuclear composition of an atom of the element.
If the number of electrons in an ion Z3– is 10, the atomic number of element Z will be :
The atomic number of an element E is 16. The number of electrons in its ion E2– will be :
The number of electrons in an ion Y2+ is 10. The atomic number of element Y is most likely to be :
What is the numerical value of Avogadro number ?
What name is given to this number ?
What is the number of molecules in 1.5 moles of ammonia ?
Calculate the number of molecules in 4 g of oxygen.
If 32 g of sulphur has x atoms, then the number of atoms in 32 g of oxygen will be :
If 12 gram of carbon has x atoms, then the number of atoms in 12 grams of magnesium will be :
What weight of oxygen gas will contain the same number of molecules as 56 g of nitrogen gas ?
(O = 16 u ; N = 14 u)
If one gram of sulphur contains x atoms, calculate the number of atoms in one gram of oxygen element.
(Atomic masses : S = 32 u ; O = 16 u)
How many grams of magnesium will have the same number of atoms as 6 grams of carbon ?
(Mg = 24 u ; C = 12 u )
A silver ornament of mass ‘m’ gram is polished with gold equivalent to 1% of the mass of silver. Compute the ratio of the number of atoms of gold and silver in the ornament.
. A sample of ethane (C2H6) gas has the same mass as 1.5 ×1020 molecules of methane (CH4). How many C2H6 molecules does the sample of gas contain?
Match the names of the Scientists given in column A with their contributions towards the understanding of the atomic structure as given in column B
| (A) | (B) | ||
| (a) | Ernest Rutherford | (i) | Indivisibility of atoms |
| (b) | J.J.Thomson | (ii) | Stationary orbits |
| (c) | Dalton | (iii) | Concept of nucleus |
| (d) | Neils Bohr | (iv) | Discovery of electrons |
| (e) | James Chadwick | (v) | Atomic number |
| (f) | E. Goldstein | (vi) | Neutron |
| (g) | Mosley | (vii) | Canal rays |
Helium atom has 2 electrons in its valence shell but its valency is not 2, Explain
