Water (D 1.00 g/mL) luminum (D = 2.70 g/mL) FIGURE 2 water are r Lead (D objects th 11.3 g/mL)- and a old and silver have higher em, the den g/cm) or densities, whereas gases have low densities. In the metric sys- sities of solids and liquids are usually expressed as grams per cubic centimeter grams per mililiter (g/ml.). The densities of gases are usually stated as grams er liter (g/L) TABLE 2.8 gives the densities of some common substances. ABLE 2.8 Densities of Some Common Substances Solids (at 25 °C) Density Density (g/mL) Gases (at 0 °C) Hydrogen Helium Methane Neon Density Liquids (g/mL) (at 25 °C) 0.26 Gasoline 0.090 0.179 0.714 0.902 Body fat Ice (at 0 °C) Muscle Sugar Bone Salt (NaCI) Aluminum 0.909 0.92 1.06 1.59 Ethanol Olive oil Water (at 4 °C) Urine Plasma (blood) Milk Blood Mercury 0.92 1.00 1.003-1.030 Nitrogen 1.03 2.16 2.70 ir Oxygen Carbon dioxide 1.06 1.96 Copper 19 Gold Calculating Density We can calculate the density of a substance from its mass and volume as shown in Sample Problem 2.11. SAMPLE PROBLEM 2.11 Calculating Density TRY IT FIRST tein (HDL) is a type of cholesterol, sometimes called "good choles- ured in a routine blood test. If a 0.258-g sample of HDL has a volume 0.215 mL what is the densitraser i, of the HDL sample?

For the pin shown in Fig. 2.5, why is the third figure determined for the length of the pin uncertain? Considering that the third figure is uncertain, explain why the length of the pin is indicated as 2.85 cm rather than, for example, 2.83 or 2.87 cm.

A gasoline station in Manila, Philippines, charges 38.46 pesos per liter of unleaded gasoline at a time when one US. dollar (USD) buys 47.15 pesos (PHP). The car you are driving has a gas tank with a capacity of 14 U.S. gallons and gets 24 miles per gallon. (a) What is the cost of unleaded gasoline in Manila in USD per gallon? (b) How much would a tankful of unleaded gasoline for your car cost in USD? (c) Suppose that you have only PHP 1255 (a day's wage for an elementary school teacher) and the car's tank is almost empty. How many miles can you expect to drive if you spend all your money on gasoline?

A supersaturated sugar solution (650.0 g sugar in 150.0 g water) is prepared to make rock candy. The solution is kept at 25C, where the solubility of sugar is 220.0 g/100 g water. A string is dipped into the solution, and in time, large crystals of sugar (rock candy) form. How many grams of solid are obtained when the solution just reaches saturation?