Q. 4 E4.1( 27 Votes )
Write answers to the following questions and explain your answers.
Explain with examples what is meant by a 'mole' of a substance.
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 a substance (n) =
(Mass of substance in grams)/(Molecular mass of substance)
the molecular mass of oxygen is 32u, and therefore 32g oxygen is 1mole of oxygen. The molecular mass of water is 18u. Therefore, 18g of water make 1 mole of water.
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If 0.2 mol of the following substances are required how many grams of those substances should be taken?
Sodium chloride, magnesium oxide,calcium carbonateMHB - Science & Technology
Write the names of the following compounds and deduce their molecular masses.
Na2SO4, K2CO3, CO2, NaOH, MgCl2, AlPO4, NaHCO3MHB - Science & Technology
Deduce the number of molecules of the following compounds in the given quantities.
32g oxygen, 90g water, 8.8g carbon dioxide, 7.1g chlorine.MHB - Science & Technology