SET. CHEMISTRY.

Date: 2015-10-07; view: 444.

1. Which of the following is true about an individual atom?

a) An individual atom should be considered to be a solid.

b) An individual atom should be considered to be a liquid.

c) An individual atom should be considered to be a gas.

d) The state of the atom depends on which element it is.

e) An individual atom cannot be considered to be a solid, liquid, or gas

2. By knowing the number of protons in a neutral element, you should be able to determine

a) The number of neutrons in the neutral element.

b) The number of electrons in the neutral element.

c) The name of the element.

d) Two of these are true.

e) None of these is true.

3. An ion is formed

a) By either adding or subtracting protons from the atom.

b) By either adding or subtracting neutrons from the atom.

c) By either adding or subtracting electrons from the atom.

d) All of these are true.

e) Two of these are true.

4. A reaction of 1 L of chlorine gas (Cl2) with 3 L of fluorine gas (F2) yields 2 L of a gaseous product. All gas volumes are at the same temperature and pressure. What is the formula of the gaseous product?

a) ClF3

b) Cl2F2

c) ClF2

d) ClF

e) None of these is true.

5. Which of the following elements has the greatest (most negative) electron affinity?

a) Ne

b) O

c) C

d) Be

e) Kr

6. What amount (moles) is represented by 20.0 mg caffeine, C8H10N4O2?

a) 2.0 × 10⁻⁴ mole

b) 1.03 × 10⁻⁴ mole

c) 2.0 × 10⁻⁶ mole

d) 1.03 × 10⁻⁶ mole

e) 6.023 × 10⁻⁶ mole

7. Aspartame is an artificial sweetener that is 160 times sweeter than sucrose (table sugar) when dissolved in water. It is marketed as Nutra-Sweet. The molecular formula of aspartame is C14H18N2O5. How many molecules are in 5.0 mg of aspartame?

a) 1.6 × 10²³ molecules

b) 1.0 × 10¹⁹ molecules

c) 5.0 × 10¹⁷ molecules

d) It is not possible to estimate the number of molecules.

e) 2.7 × 10²⁰ molecules

8. Anabolic steroids are performance enhancement drugs whose use has been banned from most major sporting activities. One anabolic steroid is fluoxymesterone (C20H29FO3). Calculate the mass percentage of C.

a) 68.29%

b) 14.26%

c) 56.48%

d) 71.40%

e) 86.89%

9. Balance the reaction:
C6H6(l) + O2(g) → CO2(g) +H2O(g)

a) 4 C6H6(l) + 13 O2(g) → 10 CO2(g) + 4 H2O(g)

b) 2 C6H6(l) + 15 O2(g) → 12 CO2(g) + 6 H2O(g)

c) Two of these are true.

d) C6H6(l) + 7 O2(g) → 2 CO2(g) + 2 H2O(g)

e) C6H6(l) + 7 1/2 O2(g) → 6 CO2(g) + 3 H2O(g)

10. What is the volume of a 12.2 g piece of metal with a density of 9.43 g/cm³?

a) 12.2 cm³

b) 1.29 cm³

c) 0.773 cm³

d) 115 cm³

e) 9.43 cm³

11. What is the correct formula for potassium sulfite?

a) KSO4

b) K2SO3

c) K2SO4

d) K2SO5

e) P2SO4

12. If 35.21 mL of 0.1894 M KOH is required to neutralize 25.00 mL of an aqueous solution of arsenic acid (H3AsO4), what is the concentration of the arsenic acid solution?
H3AsO4 (aq) + 3 KOH (aq) → K3AsO4 (aq) + 3 H2O (l)

a) 0.2668 M

b) 0.8003 M

c) 0.08892 M

d) 0.1345 M

e) 0.1778 M

13. For a substance to be considered a strong electrolyte, it must

a) Be an ionic compound.

b) Dissociate virtually completely into ions in solution.

c) Be highly soluble in water.

d) Contain both metal and nonmetal atoms.

e) Be a covalent compound.

14. Calculate the number of grams of Al2O3 that could be produced if 2.5 g of aluminum and 2.5 g of oxygen were allowed to react according to the following balanced equation.
4Al(s)+3O2(g)→2Al2O3 (s)

a) 4.7g

b) 7.4 g

c) 9.4 g

d) 5.3 g

e) 10.0 g

15. The balanced molecular equation for complete neutralization of H2SO4 by KOH in aqueous solution is

a) H2SO4 (aq)+2KOH (aq)→ 2H2O(l) + K2SO4 (s)

b) H+ (aq)+KOH(aq)→H2O(l) + K+ (aq)

c) H2SO4(aq)+2OH– (aq)→2H2O(l) + SO42– (aq)

d) H+ (aq)+OH– (aq)→ 2H2O(l)

e) H2SO4 (aq)+2KOH (aq)→2H2O(l) + K2SO4(aq)

16. Some of the molecules found in the human body are NH2CH2COOH (glycine), C6H12O6 (glucose), and CH3(CH2)16COOH (stearic acid). The bonds they form are

a) Nuclear.

b) Metallic.

c) Ionic.

d) Covalent.

e) None of the above.

17. Which substance is made up of many monomers joined together in long chains?

a) Salt.

b) Protein.

c) Ethanol.

d) Propane.

e) Methane.

18. Which of these is an example of an exothermic chemical process?

a) evaporation of water

b) melting ice

c) photosynthesis of glucose

d) combustion of gasoline

e) Both (a) and (c.)

19. Equal volumes of 1 molar hydrochloric acid (HCl) and 1 molar sodium hydroxide (NaOH) are mixed. After mixing, the solution will be

a) strongly acidic.

b) weakly acidic.

c) strongly basic.

d) weakly basic.

e) nearly neutral.

20. Of four different laboratory solutions, the solution with the highest acidity has a pH of

a) 14

b) 11

c) 7

d) 5

e) 3

21. A catalyst can speed up the rate of a given chemical reaction by

a) increasing the equilibrium constant in favor of products.

b) lowering the activation energy required for the reaction to occur.

c) raising the temperature at which the reaction occurs.

d) increasing the pressure of reactants, thus favoring products.

e) increasing the activation energy required for the reaction to occur.

22. What is the oxidation number of sulfur in BaSO4?

a) -2

b) 0

c) +1

d) +6

e) -3

23. Which statement is true for the reaction represented by this equation?
CH4 +2O2 →CO2 +2H2O

a) 1 gram of CH4 is required to react with 2 grams of O2.

b) 1 gram of CH4 is required to react with 4 grams of O2.

c) 1 mole of CH4 is required to react with 2 moles of O2.

d) 1 mole of CH4 is required to react with 4 moles of O2.

e) 1 gram of CH4 is required to react with 4 moles of O2.

24. What is the molarity of 28.9g of CaCl2 dissolved in water to make 0.78L of solution?

a) 0.33 M

b) 0.69 M

c) 1.5 M

d) 3.0 M

e) 3.5 M

25. This balanced equation represents a chemical reaction.
2C4H10 (g)+13O2 (g)→8CO2 (g)+10H2O(g)
What type of chemical reaction is represented by the equation?

a) combustion

b) decomposition

c) single replacement

d) double replacement

e) Both (b.) and (c.)

26. Which bond is most polar

a) N-H

b) C-H

c) O-H

d) H-H

e) C-H and H-H

27. What volume of a 12.0 M HCl solution is needed to provide 0.6 mol of HCl?

a) 12 mL

b) 50 mL

c) 5 mL

d) 500 mL

e) 15 mL

28. Which one of the following samples contains the largest number of atoms?

a) 2.5 mol CH4

b) 10.0 mol He

c) 7.0 mol Cl2

d) 4.0 mol SO2

e) 1.8 mol S8

29. What mass of 40.0%glucose, C6H12O6, solution contains 75.0g of water?

a) 40.0g

b) 50.0g

c) 125.0g

d) 150.0g

e) 175.0g

30. The ability of an atom in a molecule to attract electron density to itself is termed

a) paramagnetism

b) diamagnetism

c) electronegativity

d) electron affinity

e) ionization potential