Unit conversions (dimensional analysis) Knowledge-Based Practice

Questions

1. 1.

   A gas sample in a laboratory manometer exerts a pressure of 988 torr. Given that 1 atm = 760 torr and 1 atm = 101.3 kPa, what is this pressure expressed in kilopascals (kPa)?

   • A) 1.30 kPa
   • B) 77.9 kPa
   • C) 132 kPa
   • D) 9.75 kPa
2. 2.

   A piece of thin metal foil has a thickness of 0.00250 inches. Given that 1 in = 2.54 cm, what is this thickness expressed in micrometers ($\mu\text{m}$)?

   • A) 0.0635 $\mu\text{m}$
   • B) 9.84 $\mu\text{m}$
   • C) 63.5 $\mu\text{m}$
   • D) 635 $\mu\text{m}$
3. 3.

   A gaseous effluent moves through a ventilation duct at an average speed of $25.0\text{ m/s}$. Given that $1\text{ mi} = 1.609\text{ km}$, what is this speed expressed in miles per hour ($\text{mi/h}$)?

   • A) $15.5\text{ mi/h}$
   • B) $90.0\text{ mi/h}$
   • C) $145\text{ mi/h}$
   • D) $55.9\text{ mi/h}$
4. 4.

   An analytical sensor has an active surface area of 4.50 $\text{in}^2$. Given that 1 in = 2.54 cm, what is this surface area expressed in square centimeters ($\text{cm}^2$)?

   • A) 0.698 $\text{cm}^2$
   • B) 1.77 $\text{cm}^2$
   • C) 11.4 $\text{cm}^2$
   • D) 29.0 $\text{cm}^2$
5. 5.

   A thermochemical process absorbs 375,000 J of heat. What is this quantity of energy expressed in kilocalories (kcal), given that 1 cal = 4.184 J?

   • A) 1570 kcal
   • B) 89.6 kcal
   • C) 89,600 kcal
   • D) 375 kcal
6. 6.

   A laboratory chromatographic column operates at a solvent flow rate of 1.80 mL/s. What is this flow rate expressed in liters per hour (L/h)?

   • A) 0.108 L/h
   • B) 0.500 L/h
   • C) 6.48 L/h
   • D) 64.8 L/h
7. 7.

   A sample of an unknown liquid has a density of 0.850 g/cm3. What is this density expressed in kilograms per cubic meter (kg/m3)?

   • A) 0.000850 kg/m3
   • B) 0.850 kg/m3
   • C) 85.0 kg/m3
   • D) 850 kg/m3

Answers and step-by-step solutions appear after you finish the test.