Practice Questions - Water

1. A sample of air contains 200 ppm of water. Express this quantity of water as a percentage.
(A) 0.02%
(B) 200%
(C) 2 X 10^-6 %
(D) 2%
(E) 200 x 10^-6 %

2. Hydrogen chloride gas molecules are polar and covalent compounds. An aqueous solution of HCl conducts electricity. How?
(A) HCl ionizes in water
(B) HCl molecules carry electrons from one electrode to the other electrode
(C) water molecules carry electrons from one electrode to the other electrode
(D) HCl molecules and water molecules carry the current

3. What acid is found in car battery fluid?
(A) sulfuric acid
(B) hydrochloric acid
(C) citric acid
(D) acetic acid

4. Under which of the following sets of conditions could the most oxygen be dissolved in water?
Pressure of O₂(g)____ Temperature
Above H₂O(l) _________of H₂O(l)
(atm) ________________°(C)

(A) 5.0 __________________80
(B) 5.0 __________________20
(C) 1.0 __________________80
(D) 1.0 __________________20
(E) 0.5 __________________20

5. Water is a polar molecule. This means that
(A) the opposite ends of the molecule have opposite charges.
(B) water molecules are linear, like a pole.
(C) water is one of the many hydrophobic molecules.
(D) the atoms in water have electronegativities that are equal.
(E) all of the above

6. On a mountaintop, it is observed that water boils at 90°C, not at 100°C as at sea level. This phenomenon occurs because on the mountaintop the
(A) equilibrium water vapor pressure is higher due to the higher atmospheric pressure
(B) equilibrium water vapor pressure is lower due to the higher atmospheric pressure
(C) equilibrium water vapor pressure equals the atmospheric pressure at a lower temperature
(D) water molecules have a higher average kinetic energy due to the lower atmospheric pressure
(E) water contains a greater concentration of dissolved gases

7. The smallest particle of water is
(A) an atom.
(B) a molecule.
(C) a crystal.
(D) an element.
(E) a compound.

8. Most of water's unique properties result from the fact that water molecules
(A) are in constant motion.
(B) are very small.
(C) tend to stick together.
(D) tend to repel each other.
(E) are extremely large.

9. Ice floats because
(A) its hydrogen molecules bond to the water surface film.
(B) it is colder than liquid water.
(C) its molecules are moving faster than in liquid water.
(D) its water molecules are farther apart than in liquid water.
(E) it is more dense than liquid water.

10. Of the following molecules, which has the largest dipole moment - in other words, which one is the most polar?
(A) N₂
(B) CO₂
(C) O₂
(D) HF
(E) F₂

11. The smallest particle of an element that has the chemical characteristics of that element is a (n)
(A) atom.
(B) proton.
(C) neutron.
(D) electron.
(E) molecule.

12. The weak attraction between two water molecules is called a(n)
(A) covalent bond.
(B) hydrogen bond.
(C) electrical bond.
(D) ionic bond.
(E) polar covalent bond.

13. Which of these is a NOT a compound?
(A) H₂0
(B) H₂
(C) NaCl
(D) NO₂
(E) C₆H₁₂ O₆

14. Which of the following is not a chemical reaction?
(A) Sugar and oxygen gas combine to form carbon dioxide and water.
(B) Solid ice melts to form liquid water.
(C) Hydrogen gas combines with oxygen gas to form liquid water.
(D) Sodium metal and chlorine gas (Cl₂) unite to form sodium chloride.
(E) Sulfur dioxide and water vapor join to form sulfuric acid.

15. Sodas typically contain sugar, flavorings, coloring agents, and carbon dioxide dissolved in water. The best term to describe this mixture would be
(A) a solute.
(B) a solution.
(C) a solvent.
(D) hydrophobic.
(E) an aqueous solution.

16. Which of the following is the correct formula for magnesium chloride?
(A) MgCl
(B) MgCl₂
(C) MgCl₃
(D) Mg₂Cl
(E) MnCl

17. What is the correct name of Na₂CO₃?
(A) nitrogen carbide
(B) sodium trioxide
(C) sodium carbon trioxide
(D) sodium carbonate
(E) sodium carbide

18. What is the best answer to the question, "Waiter, what's this fly doing in my soup?"
(A) "That's surprising. The fly is supposed to be on the main course!"
(B) "The back stroke, sir."
(C) "Be quiet, everyone will want one!"
(D) "I told the chef not to strain the soup through the fly swatter!"
(E) "Don't worry, how much can a fly drink?"

19. Which of the following would NOT be classified as acidic?
(A) HCl
(B) Pepsi-Cola
(C) Ca(OH)₂
(D) vinegar
(E) lemon juice

20. What is the product when Na₂SO₄ is dissolved in water?
(A) Na₂O and SO₃
(B) S, O, and Na ions
(C) Na⁺ and SO₄^-2 ions
(D) SO₄ and hydrogen gas
(E) N⁺ and SO^-

21. Which of these is NOT an important characteristic of water for living organisms?
(A) produces CO₂ in the body
(B) cushions and lubricates
(C) dissolves molecules to allow chemical reactions
(D) transports molecules
(E) stabilizes body temperature

22. In 100 grams of a 25% sugar solution by mass, there are
(A) 25 grams of sugar and 75 grams of water.
(B) 25 grams of sugar and 100 grams of water.
(C) 25 grams of water and 75 grams of sugar.
(D) 100 grams of sugar and 25 grams of water.

23. Which reaction below is NOT balanced? (In a balanced equation, the # of each type of atom on the reactant side = the # of each type of atom on the product side)

(A) 2C + O₂ ----> 2CO

(B) 2 H₂ + O₂ -----> 2 H₂O

(C) C + O₂ -----> CO

(D) 2 Na + Cl₂ -----> 2 NaCl

(E) 2 Cu + O₂ ------> 2 CuO


24. What is conserved when one balances a chemical equation?
(A) molecules
(B) atoms
(C) substances
(D) reactants
25. The symbol Na⁺ indicates that a sodium atom has
(A) gained an electron.
(B) gained a proton.
(C) gained a neutron.
(D) lost an electron.
(E) lost a proton.

26. Which has the LOWEST pH?
(A) normal (non-acid) rain
(B) a concentrated solution of NaOH
(C) rain in western Pennsylvania
(D) human blood
(E) a concentrated solution of H₂SO₄

27. Which reaction below is balanced?

(A) C + O₂ ----> CO

(B) H₂ + O₂ -----> 2 H₂O

(C) CH₄ + 2 O₂ ------> CO₂ + 2 H₂O

(D) C₆H₁₂+ 6 O₂ -------> 3 CO₂

(E) Cu + O₂ -----> 2 CuO

28. In the famous chemistry poem "Johnny was a good boy, but Johnny is no more, what Johnny thought was H₂O was H₂SO₄", what is H₂SO₄?
(A) Fresca
(B) Sulphuric Acid
(C) Coordinates in "Battleship"

29. Why do we say that the neutron is "neutral"?
(A) It steadfastly refuses to get into the petty squabbles the protons and electrons constantly have
(B) It has neither a positive nor negative electric charge
(C) It's the official Sub-Atomic particle of Switzerland

30. What is the correct name of K₃PO₄?
(A) phosphorus oxide
(B) potassium tetroxide
(C) potassium phosphorus tetroxide
(D) phosphorus carbide
(E) potassium phosphate


ANSWERS

1-A 2-A 3-A 4-B 5-A 6-C 7-B 8-C 9-D 10-D 11-A 12-B 13-B 14-B 15-B 16-B 17-D 18-any 19-C 20-C 21-A 22-A 23-C 24-B 25-D 26-E 27-C 28-B 29-B 30-E