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- Which of the following statements is a hypothesis about the synthesis of gold nanoparticles? (LO 1.1) (a) Adding a salt solution to gold nanoparticles causes the color to change from red to blue. (b) To examine the effect of salt on gold nanoparticles, variable concentrations of salt are added to the nanopar-ticles and the results are measured (c) A solution of gold nanoparticles with an average diam-eter of 30 nm has a wavelength of maximum absorption of 450 nm and is a reddish-orange color. (d) Adding a substance with a negative charge to the surface of the nanoparticles creates repulsive forces that stabilize small particle size
Problem 1
- Convert 0.055 milliseconds to seconds, and write the answer in scientific notation. (LO 1.3) (a) 5.5 * 10-3 s (b) 5.5 * 10-4 s (c) 5.5 * 10-5 s (d) 5.5 * 10-7 s
Problem 2
- Which quantity represents the largest mass? (LO 1.4) (a) 2.5 * 107 mg (b) 2.5 * 102 mg (c) 2.5 * 108 ng (d)2.5*10-3kg
Problem 3
Problem 4a
A mammalian HELA cell has a diameter of 2 * 10-5 m. Report the diameter of the cell using the most appropriate prefix on the base unit of meter. (LO 1.5) (a) 2 µm
Problem 4b
A mammalian HELA cell has a diameter of 2 * 10-5 m. Report the diameter of the cell using the most appropriate prefix on the base unit of meter. (LO 1.5) (b) 20 µm
Problem 4c
A mammalian HELA cell has a diameter of 2 * 10-5 m. Report the diameter of the cell using the most appropriate prefix on the base unit of meter. (LO 1.5) (c) 200 nm
Problem 4d
A mammalian HELA cell has a diameter of 2 * 10-5 m. Report the diameter of the cell using the most appropriate prefix on the base unit of meter. (LO 1.5) (d) 0.2 mm
Problem 5a
The temperature on the surface of the Sun is 5778 K. What is the temperature in degrees Fahrenheit? (LO 1.6) (a) 3344 °F
Problem 5b
The temperature on the surface of the Sun is 5778 K. What is the temperature in degrees Fahrenheit? (LO 1.6) (b) 3040 °F
Problem 5c
The temperature on the surface of the Sun is 5778 K. What is the temperature in degrees Fahrenheit? (LO 1.6) (c) 10,920 °F
Problem 5d
The temperature on the surface of the Sun is 5778 K. What is the temperature in degrees Fahrenheit? (LO 1.6) (d) 9941 °F
- Calculate the volume in liters of a rectangular object with dimensions 13.0 cm * 11.0 cm * 12.0 cm. (a) 1720 L (b) 1.72 L (c) 14.3 L (d) 2.41 L
Problem 6
- A 25.5 g sample of a metal was placed into water in a gradu-ated cylinder. The metal sank to the bottom, and the water level rose from 15.7 mL to 25.3 mL. What is the identity of the metal? (LO 1.9) (a) Tin (density = 7.31 g/cm3) (b) Lead (density = 11.34 g/cm3) (c) Silver (density = 10.49 g/cm3) (d) Aluminum (density = 2.64 g/cm3)
Problem 7
- Consider 20 mL samples of the following liquids. Which sample has the largest mass? (LO 1.9) (a) Water (density = 1.0 g/mL) (b) Glycerol (density = 1.26 g/mL) (c) Ethanol (density = 0.79 g/mL) (d) Acetic acid (density = 1.05 g/mL
Problem 8
- The cylinder contains two liquids that do not mix with one another: water (density = 1.0 g/mL) and vegetable oil (density = 0.93 g/mL). Four different pieces of plastic are added to the cylinder. Which type of plastic is at the position indicated by the square object in the figure? (LO 1.10) (a) Polyvinyl chloride (density = 1.26 g/mL) (b) Polypropylene (density = 0.90 g/mL) (c) High-density polyethylene (density = 0.96 g/mL) (d) Polyethylene terephthalate (density = 1.38 g/mL)
Problem 9
Problem 10
An electron with a mass of 9.1 * 10-28 g is traveling at 1.8 * 107 m/s in an electron microscope. Calculate the kinetic energy of electron in units of joules, and report your answer in scientific notation. (LO 1.11) (a) 1.5 * 10-16 J (b) 1.6 * 10-20 J (c) 2.9 * 10-13 J (d) 2.9 * 10-10 J
- Report the reading on the buret to the correct number of significant figures. (LO 1.15) (a) 1 mL (b) 1.4 mL (c) 1.40 mL (d) 1.400 mL
Problem 11
- A scientist uses an uncalibrated pH meter and measures the pH of a rainwater sample four times. A different pH meter was calibrated using several solutions with known pH. The true pH of the rain was found by the calibrated pH meter to be 5.12. What can be said about the level of accuracy and precision of the uncalibrated pH meter? (LO 1.14)
Problem 12
