Verbal and Nonverbal Communication in the Class Room

Teacher Notes Name Key Class Date

Gas Laws I
Dalton and Boyle NOTE: This is probably the first gas law worksheet given to students. Impress on them the need to take their time and follow the steps as stated in the instructions at least until they have some experience in this type problem solving. Many mistakes can be corrected early if students take the time to think about what size answer would be reasonable. For example, in question 2 if the pressure is decreasing, the volume must be increasing. A reasonable answer must be greater than 9.65 L. 1. 2. What will be the volume of a balloon at 98 kPa if its volume is 9.65 L at 235 kPa? P1 V1 P2 (Boyle’s) P1V1 = P2V2 V2 = P1V1 / P2 V2 = (9.65L) (235 kPa)/ (98 kPa) V2 = 23 L V1 P1 4. An exhaled air bubble underwater at 290. kPa has volume 18.9 mL. What will be its volume at the water’s surface where the pressure is 104 kPa. (Why must a diver exhale during ascent?) P
2

3. What pressure is required to reduce the volume of gases in a car’s cylinder from 48 cm3 at V1 102 kPa to 5.2 cm3? V2 P1

(Boyle’s) P1V1 = P2V2 P2 = P1V1/V2 P2 = (102 kPa)(48cm3)/(5.2cm3) P2 = 940 kPa

(Boyle’s) P1V1 = P2V2 V2 = P1V1 / P2 V2 = (290.kPa)(18.9mL)/(104kPa) V2 = 52.7mL Divers must exhale or else the gas in their lungs will expand so much that his lungs could rupture.

5. ,

V1 P1 6. A gas sample has volume 3.00 dm3 at 101 kPa. What will be the volume if the pressure is reduced to 14.2 kPa? P2 (Boyle’s) P1V1 = P2V2 V2 = P1V1/ P2 V2 = (9.24 dm3)(101 kPa)/(14.2 kPa) V2 = 65.7 dm3