Advertisements
Advertisements
प्रश्न
Calculate the number of molecules in 4 g of oxygen.
Advertisements
उत्तर
Mass of oxygen = 4g
We know that 32g of oxygen contain 6.022 × 1023 molecules.
Number of molecules in 32g of oxygen = 6.022 × 1023
Number of molecules in 4g of oxygen = 4 × 6.022 × 1023/32
Hence, 4g of oxygen have 7.52 × 1022 molecules.
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 atom of an element X contains 17 protons, 17 electrons and 18 neutrons whereas the atom of an element Y contains 11 protons, 11 electrons and 12 neutrons.
- What type of ion will be formed by an atom of element X ? Write the symbol of ion formed.
- What will be the number of (i) protons (ii) electrons, and (iii) neutrons, in the ion formed from X ?
- What type of ion will be formed by an atom of element Y ? Write the symbol of ion formed.
- What will be the number of (i) protons (ii) electrons, and (iii) neutrons, in the ion formed from Y ?
- What is the atomic mass of (i) X, and (ii) Y ?
- What could the elements X and Y 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 ?
If 12 gram of carbon has x atoms, then the number of atoms in 12 grams of magnesium will be :
Which of the following has the maximum number of atoms ?
What weight of oxygen gas will contain the same number of molecules as 56 g of nitrogen gas ?
(O = 16 u ; N = 14 u)
What mass of nitrogen, N2, will contain the same number of molecules as 1.8 g of water, H2O ?
(Atomic masses : N = 14 u ; H = 1 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 gold sample contains 90% of gold and the rest copper. How many atoms of gold are present in one gram of this sample of gold?
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?
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?
In the atom of an element X, 6 electrons are present in the outermost shell. If it acquires noble gas configuration by accepting requisite number of electrons, then what would be the charge on the ion so formed?
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 |
