Chapter 2, Problem 11PP

If the value of mass doubles but the volume stays the same, the value for density will be

When determining CFUs for a dilution of the same sample at 10-2 and 10-3 which of the following results would seem the most accurate to you? Explain why in the space below. A. 110,000 CFU/mL for 10-2; and 140,000 CFU/mL 10-3 B. 110,000 CFU/mL for 10-2; and 14,000 CFU/mL 10-3 C. 10,000 CFU/mL for 10-2; and 140,000 CFU/mL 10-3 D. none of the above

A volumetric flask made of Pyrex glass is calibrated at 20 °C.It is filled to the 100 mL mark with 35 °C acetone. After the flask is filled the acetone cools and the flask warms so that the combination of acetone and flask reaches a uniform temperature of 32 °C. The combination is then cooled to 20 °C. a) What is the volume of the acetone when it is at 20 °C? b)At the temperature of 32 °C, does the level of acetone lie above or below the 100 mL mark?