Calculate the relative molecular weights of substances according to their formulas: Br2, H2O, CO2, H2SO

univerkov | June 17, 2021 | education

Calculate the relative molecular weights of substances according to their formulas: Br2, H2O, CO2, H2SO, KOH, BaCl2. Find the values of the relative atomic masses according to D.I.Mendeleev’s table, round them to whole numbers (except for chlorine, Ar (Cl) = 35.5).

Mr (H2O) = 2 * Ar (H) + Ar (O) = 2 * 1 + 4 * 16 = 18
Mr (CO2) = Ar (C) + 2 * Ar (O) = 12 + 2 * 16 = 32 + 12 = 44
Mr (Br2) = 2 * Ar (Br) = 2 * 80 = 160
Mr (H2SO) = 2 * Ar (H) + Ar (S) + Ar (O) = 2 * 1 + 32 + 16 = 50
Mr (KOH) = Ar (K) + Ar (O) + Ar (H) = 39 + 16 + 1 = 56
Mr (BaCl2) = Ar (Ba) + 2 * Ar (Cl) = 137 + 2 * 35.5 = 208
Mr (H2SO4) = 2 * Ar (H) + Ar (S) + 4 * Ar (O) = 2 * 1 + 32 + 4 * 16 = 64 + 34 = 98

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