1.54 Label each of the following as either a homogeneous mixture or a heterogeneous mixture:
a. gasoline c. concrete
b. vegetable soup
d. hot coffee
1.58 Label each of the following as either a physical change or a chemical reaction:
a. A puddle of water evaporates.
b. Food is digested.
c. Wood is burned.
1.60 Label each of the following properties of sodium as either a physical property or a chemical property:
a. When exposed to air, sodium forms a white oxide.
b. The density of sodium metal at 25°C is 0.97 g/cm3.
1.62 Label each of the following as either a pure substance or a mixture:
a. sucrose (table sugar)
b. orange juice
1.78 Determine the temperature reading of the following thermometer to the correct number of significant figures.
1.106 If a drop of blood has a volume of 0.05 mL, how many drops of
blood is in the adult described in Question 1.105?
1.108 A newborn is 21 in in length and weighs 6 lb 9 oz. Describe the
baby in metric units.
1.122 The weather station posted that the low for the day would be −10.0°F. Convert −10.0°F to:
1.124 Convert 300.0 K to:
1.128 Calculate the density of 50.0 g of an isopropyl alcohol–water mixture (commercial rubbing alcohol) that has a volume of 63.6 mL.
1.30 Why is observation a critical starting point for any scientific study?