Question

1. How many photons at 586 nm must be absorbed to melt 6.55 × 10² g of ice?
(It takes 334 J to melt 1 g of ice at 0° C. On average, how many H₂O molecules does one photon convert from ice to water?

2. The highest speed limit in the United States is 85.0 mph on an isolated stretch of rural interstate in Texas. What is the speed limit in kilometers per hour? (1 mi = 1609 m). Report your answer as a whole number.

3. A piece of metal with a mass of 22.1 g was dropped into a graduated cylinder containing 16.00 mL of water. The graduated cylinder after the addition of the metal is shown. Determine the density of the metal.

4. A lead sphere has a mass of 1.24 × 10⁴g, and its volume is 1.10 ×10³ cm³. Calculate its density.

5. Calculate the percent error for the following measurements: (a) The density of alcohol (ethanol) is found to be 0.8044 g/mL (true value = 0.7980 g/mL).  %(b) The mass of gold in an earring is analyzed to be 0.8455 g (true value = 0.8644 g).%

Answer 1