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Molarity to molality: m = 1000M/(1000d - MM_s), where d = density (g/mL), M_s = solute molar mass. Molarity from density and mass%: M = 10dw%/M_s. Molarity to mole fraction: x_solute = MM_solvent/(1000d) approximately for dilute solutions. Normality = M x n-factor. Dilution: M1V1 = M2V2 (moles conserved). Mixing solutions of same solute: M_f = (M1V1 + M2V2)/(V1+V2). Mixing acid and base: find meq of each, subtract, divide by total volume. If meq(acid) > meq(base): solution is acidic, [H+] = excess meq / total V(mL) x 10^-3. Weight/volume %: g solute per 100 mL solution. Volume/volume %: mL solute per 100 mL solution. ppm: mg/L for aqueous (since density ≈ 1). ppb: micrograms/L. Molarity is temperature-dependent (volume changes). Molality, mole fraction, mass%, ppm are temperature-independent.