In the preparation of a certain alkyl halide, 10 g of sodium bromide (NaBr), 10 mL distilled water (H20), and 9 mL 3-methyl-1-butanol (C5H120) were mixed in the round-bottomed flask and allowed to cool for 2 -3 minutes. Then while swirling the flask, 10 mL sulfuric acid (H2SO4) was slowly added to the flask and the mixture was refluxed and later distilled. The mass of the pure product obtained was 6.48 g. Sodium hydrogen carbonate (NaHCO3) was used to remove impurities. (Density of 3-methyl-1-butanol is 0.810 g/mL). The percentage yield will be?