8. How many minutes does it take light from the sun to reach Earth? (The distance from the sunto Earth is 93 million miles; the speed of light is 3.00 × 108m/s)(4 points)(Reference: Chang 1.43)93 x 10^6 mi x 1609 m= 1.496 x 10^11 m1 mi 1.496 x 10^11 m x 1 s = 498.667 s 3.00 x 10^8 m 498.667 s x 1 min= 8.3 mins60 s9.Normal body temperature is 78.0°F. Calculate this temperature in degrees Celsius and Kelvin. (4 points)(5 C / 9 F) x ( C- 32 F ) = C(5 / 9 ) x ( 78 - 32 ) = 25.56 C( C + 273.15 K) x ( 1 K / 1 C ) = K(25.56 + 273.15) x (1/1) = 298.71 K10.Bromine is a reddish-brown liquid. Calculate its density (in g/mL) if 586 g of the substance occupies 188 mL. (4 points)(Reference: Chang 1.21)586 g= 3.117g/mL = 3.12 g/mL188mL

11.Aluminum is a lightweight metal (density = 2.70 g/cm3) used in aircraft construction, high-voltage transmission lines, beverage cans, and foils. What is its density in kg/m3? (4 points)(Reference: Chang 1.51)2.70 gx 0.001 kg= .0027 kgcm31 g cm3.0027 kgx 1 cm3= 2.7 x 10 ^ -9 kgcm3m3m312.Calculate the mass of a cube of platinum of edge length 0.040 mm (the density of platinum = 21.4 g/cm3). (5 points)(Reference: Chang 1.57)0.040 mm x .1 cm= .0040 cm1mmV = (.0040cm)^3 = 6.4 x 10^ -8 cm321.4 g x 6.4 x 10^ -8 cm3 = 1.4 x 10^ -6 gcm313.A piece of silver (Ag) metal weighing 194.3 g is placed in a graduated cylinder containing 242.0 mL of water. The volume of water now reads 260.5 mL. From these data calculate the density of silver in units of g/mL. (5 points)(Reference: Chang 1.61)Mass- 194.3gVolume- 260.5mL - 242.0mL = 18.5mL194.3g = 10.5 g/mL18.5mL

14.Cholesterol in blood is measured in milligrams of cholesterol per deciliter of blood. If the average adult has 6.0 liters of blood, how many grams of cholesterol would be in the blood of an average adult with a cholesterol reading of 185 mg/dL? Density of blood = 1.020 g/mL. (5 points)6 L x 10 dL= 60 dL1 L185 mgx 60 dL = 11100 mg1 dL11100mg x .001g= 11.1g1mg

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- Summer '14
- Chemistry, SI prefix, Kilogram, Litre