Chapter 1 Elements , Compounds and Solutions Review

Which pair of elements is matched with the correct chemical symbols?

• Fluorine, F, and argon, Ag

• Fluorine, F, and iodine, I

• Sulfur, Su, and bromine, Br

• Nitrogen, Ni, and argon, Ar

Which of the set of actions is more likely to increase the rate of dissolution of a pill in water?

• hot water, crush pill, stir constantly

• hot water, crush pill, stir occasionally

• hot water, cut pill in half, stir constantly

• warm water, crush pill, stir at the beginning

The diagram shows one molecule of caffeine. A caffeine molecule has 8 atoms of ________________, 10 atoms of ________________, 4 atoms of ________________, and ________________ atoms of ________________.

• 8 atoms of carbon, 10 atoms of hydrogen, 4 atoms of nitrogen, and 2 atoms of oxygen.

• 6 atoms of carbon, 12 atoms of hydrogen, 4 atoms of nitrogen, and 2 atoms of oxygen.

• 8 atoms of carbon, 8 atoms of hydrogen, 4 atoms of nitrogen, and 4 atoms of oxygen.

• 7 atoms of carbon, 10 atoms of hydrogen, 5 atoms of nitrogen, and 2 atoms of oxygen.

Scientists commonly work with corrosive acids in the laboratory, being careful to wear gloves and safety goggles or respirators to protect their skin and airways. Other acids are much weaker and are even found in common foods and drinks. The following table lists the names, chemical formulas, and common uses for four different acids. Acid Name | Chemical Formula | Common Uses Perchloric acid | HClO4 | Fireworks, vehicle airbag initiators Acetic acid | HC2H3O2 | Main vinegar ingredient Sulfuric acid | H2SO4 | Fertilizers Carbonic acid | H2CO3 | Carbonated drink ingredient.

• Perchloric acid contains sulfur atoms.

• Acetic acid contains the most atoms.

• A molecule of sulfuric acid contains one hydrogen atom.

• Carbonic acid is the main ingredient in vinegar.

Reference the following two drawings. Which of the following statements is true?

• The element square from the periodic table with atomic number 7 is nitrogen.

• Both the element square and the atom drawing represent the same element.

• The atom drawing shown is nitrogen.

• None of these statements is true.

You place 1 g of sugar in each of three beakers. You add 100 mL of water to each beaker. In Beaker 1, the water is cold. In Beaker 2, the water is at room temperature. In Beaker 3, the water is hot. Every 3 minutes you estimate how much of the sugar has dissolved. You summarize your data in this table: | Water temperature | % dissolved after 3 minutes | % dissolved after 6 minutes | % dissolved after 9 minutes | |--------------------------|-----------------------------|-----------------------------|-----------------------------| | cold water | 10 | 20 | 25 | | room temperature water | 20 | 30 | 50 | | hot water | 30 | 70 | 100 | Which of the following four graphs has the data plotted correctly?

• Table 1

• Table 2

• Table 3

• Table 4

Reference the following four drawings of different atoms. Arrange the atoms in the drawings from lowest atomic number to highest atomic number.

• Al, Ar, As, Na

• Ar, As, Na, Al

• Na, Al, Ar, As

• Na, Al, As, Ar

The chemical formula for chocolate is C7H8N4O2. Use a periodic table to identify the types and number of each atom that makes up C7H8N4O2.

• 7 carbon atoms, 8 hydrogen atoms, 4 nitrogen atoms, and 2 oxygen atoms

• 7 cobalt atoms, 8 hydrogen atoms, 4 nitrogen atoms, and 2 oxygen atoms

• 7 carbon atoms, 8 helium atoms, 4 nitrogen atoms, and 2 oxygen atoms

• 7 cobalt atoms, 8 helium atoms, 4 neon atoms, and 2 oxygen atoms

Which of the following is an example of a chemical change?

• blending milk and a banana to make a smoothie

• breaking a rock

• rotting banana

• hammering metal into a sheet

Examine the following four figures showing solutions containing different amounts of a solute dissolved in different amounts of water. Based on the diagrams labeled A, B, and C, which solution is the most concentrated?

• 25 g of solute in 200 mL water

• 30 g of solute in 200 mL water

• 25 g of solute in 100 mL water