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प्रश्न
Explain with examples what is meant by a 'mole' of a substance.
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उत्तर
A mole is the quantity of a substance whose mass in grams is equal in magnitude to the molecular mass of that substance in Daltons. Thus, the molecular mass of oxygen is 32 u, and therefore 32g oxygen is 1 mole of oxygen. The molecular mass of water is 18u. Therefore, 18g of water makes 1 mole of water.
1 mole of a compound is the mass of that substance in grams equal in magnitude to its molecular mass. The SI unit is mol.
Number of moles of substances (n) = `"Mass of substance in grams"/"Molecular mass of substance"`
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संबंधित प्रश्न
A gas cylinder can hold 1 kg of hydrogen at room temperature and pressure
1) Find the number of moles of hydrogen present.
2) What weight of CO2 can the cylinder hold under similar conditions of temperature and pressure? (H = 1, C = 12, O = 16)
3) If the number of molecules of hydrogen in the cylinder is X, calculate the number of CO2 molecules in the cylinder under the same conditions of temperature and pressure.
4) State the law that helped you to arrive at the above result.
What is a group of 6.022 × 1023 particles known as ?
Define mole. What are the two things that a mole represents.
If 0.2 mol of the following substance is required how many grams of that substance should be taken?
Sodium chloride
Prove the Following :
One mole of any gas contains th e same number of molecules.
Explain the term:
Gram mole
Fill in the blank
One gram atom of an element contains ______ atoms.
Calculate the weight of one molecule of oxygen.
[Avogadro’s number = 6 × 1023, O = 16 ]
A sample of ammonium nitrate when heated yields 8.96 litres of steam (measured at STP)
NH4NO3 → N2O + 2H2O
What mass of ammonium nitrate should be heated to produce 8.96L of steam?
Define the term:
Relative molecular mass
Define the term:
Gram atom
How many grams of Al are present in 0.2 mole of it?
Calculate the mass of 0.1 mole of the following:
Mg
(Ca = 40, Na = 23, Mg = 24, S = 32, C = 12, Cl = 35.5, O = 16, H = 1)
What mass of Ca will contain the same number of atoms as are present in 3.2 g of S?
The molecular formula for elemental sulphur is S8.In a sample of 5.12 g of sulphur:
How many molecules and atoms are present?
Correct the statement, if required.
The relative atomic mass of an element is the number of times one molecule of an element is heavier than `1/12` the mass of an atom of C12.
Calculate the number of moles in 7g of nitrogen.
What is Molar volume of a gas?
The number of atoms present in 0.1 mole of P4 (at. mass = 31) is ______.
Deduce the number of molecules of the following compound in the given quantity.
8.8g carbon dioxide
