Test your skills on the following problems.
Practice: The barium content of a metal ore was analyzed several times by a percent composition process.
a) Calculate the mean, median and mode.
b) Calculate the standard deviation.
Practice: Determine which of the following represents a physical change and a chemical change.
Practice: Answer each of the following questions based on the images provided below.
a) Which of the following images represents an elemental gas?
b) Which of the following images represents a heterogeneous mixture?
c) Which of the following images represents a liquid?
Practice: Which of the following represents a physical property?
a) Mercury is a liquid at room temperature.
b) Alkanes burn spontaneously.
c) CO2 (s) -----> CO2 (g)
d) 2 H2 (g) + O2 (g) -----> 2 H2O (g)
e) The rusting of a car.
Practice: A cigarette lighter contains the substance butane, C4H10, with the given properties.
a) The lighter contains 10 g of butane
b) the density of butane is 0.57 g/cm3
c) The freezing point of the butane is -138oC
d) Butane is combustible in air.
i) Which of the following features is a chemical change?
ii) Which of the following properties are intensive properties?
Practice: Which of the following properties about an unknown metal represent chemical properties?
I. It has a bluish-green color.
II. Upon exposure to air the metal experiences corrosion.
III. It has a density of 4.36 g/cm3.
IV. It has a boiling point of 522oC.
V. It conducts electricity.
Practice: An empty flask has a volume of 250 mL. When water is placed inside the flask (d = 0.9983 g/mL) the volume is 124.3 mL. What is the mass (in grams) of the water inside the flask?
Practice: If a statue at an art gallery is covered in 279 kg of copper. If the copper on the statue has a thickness of 0.0055 cm, what surface area is covered (in square meters)? Copper has a density of 8.96 g/cm3.
Practice: A Volkswagen diesel engine consumes diesel at a rate of 20.17 L per hour. If the density of the diesel is 0.850 g/mL. What is the mass (in mg) of diesel needed to drive for a continuous 4.3 hours?
Practice: If the charge and mass of one proton is 1.60218 x 10-19 C and 1.673 x 10-30 g respectively, what is the charge of 378 kg of protons.
Practice: A cylindrical tube has a length that is 15.2 cm and is filled with bromine liquid. If the mass of the bromine is 112.3 g and has a density of 25.3 g/mL. What is the inner diameter of the glass tube? ( V = π • r2 • h )
Practice: A large body of water contaminated with lead has an average depth of 750 m, a total area of 1.25 x 105 km2, and an average of 5.8 x 10-12 g/L of dissolved lead. How many milligrams of lead are in this large body of water?
Practice: Calculate the mass (in grams) of a golden sphere with a diameter of 30.0 mm. The density of gold is 19.3 g/cm3. (Vsphere = 4/3 π r3).