Chapter 6 lecture notes PDF

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chapter 6 notes...

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Chem 1070 chapter 6 What is a mole - One mole of anything is 6.022 × 10^23 units of that thing. - Also called avogadro’s number Molar mass - Molar mass is the mass of 1 mole of atoms of an element. - Atomic mass is the average mass of all atoms of an element. Molar mass of elements - Molar mass is the mass of 1 mole of atoms of an element 1 amu = mass of 1 nuclear particle Atoms -> compounds - Compound - material formed of two or more elements in definite proportions. Compounds can be decomposed to elements and/or simpler compounds. Mass of an element in a compound - Chemical formula gives the whole-number ratio of moles of element in the compound Mass percent of an element - To calculate percentage we divide the part (mass of element) by the whole (mass of compound) - Mass percent composition or mass percent of an element is the element’s percentage of the total mass of the compound. Empirical formula - Empirical formula is the simplest whole-number ratio - Laboratory analysis often provide masses of each element in a compound, not chemical formulas - Knowing the ratios between masses of elements we can obtain empirical formula for a compound. Empirical formula vs. molecular formula - Molecular Formula: C2H4O2 Acetic acid (vinegar) - Specific # atoms in a compound. - Empirical Formula: C1H2O1 Smallest whole-number ratios (many compounds)...