Advertisements
Advertisements
Question
What weight of oxygen gas will contain the same number of molecules as 56 g of nitrogen gas ?
(O = 16 u ; N = 14 u)
Advertisements
Solution
Mass of nitrogen gas = 56g
We know that equal moles of all substances contain equal number of molecules. (1 mole of all substances contains 6.022 × 1023 molecules).
The first step will be to convert 56g nitrogen gas into moles.
1 mole nitrogen gas N2 = 28g
28g nitrogen = 1 mole
56g nitrogen = 2 moles
Since, equal moles of all substances contain equal number of molecules, 2 moles of nitrogen will have the same number of molecules as 2 moles of oxygen.
The next step will be to find the mass of 2 moles of oxygen in grams.
1 mole of oxygen = 32g
2 moles of oxygen = 32 × 2 = 64g
Hence, 64g oxygen will contain the same number of molecules as 56g nitrogen gas.
APPEARS IN
RELATED QUESTIONS
If the number of electrons in an ion Z3– is 10, the atomic number of element Z 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 the number 6.022 × 1023 ?
What name is given to this number ?
Which of the following has the maximum number of atoms ?
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)
The mass of one atom of an element X is 2.0 × 10–23 g.
Calculate the atomic mass of element X.
What could element X be ?
Classify each of the following on the basis of their atomicity.
- F2
- NO2
- N2O
- C2H6
- P4
- H2O2
- P4O10
- O3
- HCl
- CH4
- He
- Ag
Which has more number of atoms?
100g of N2 or 100 g of NH3
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?
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.
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 |
The atomic number of calcium and argon are 20 and 18 respectively, but the mass number of both these elements is 40. What is the name given to such a pair of elements?
Helium atom has 2 electrons in its valence shell but its valency is not 2, Explain
An element X has a mass number 4 and atomic number 2. Write the valency of this element?
