1) A sample of oxygen gas in a closed system has a volume of 200 milliliters at 600K. If the pressure is held constant and the temperature is lowered to 300K, the new volume of the gas will be

1. 100 mL
2. 200 mL
3. 300 mL
4. 400 mL

2) Which sample of watrer will have the highest vapor pressure?

1. 10.0 mL at 62^oC
2. 20.0 mL at 52^oC
3. 30.0 mL at 42^oC
4. 40.0 mL at 32^oC

3) Which statement best describes the molecules of H₂O in the solid phase?

1. They move slowly in a straight line.
2. They move rapidly in straight lines.
3. They are arranged in a regular geometric pattern.
4. They are arranged in a random pattern.

4) What happens when a substance melts?

1. It changes from a solid to a liquid, and heat is absorbed.
2. It changes from a solid to a liquid, and heat is released.
3. It changes from a liquid to a solid, and heat is absorbed
4. It changes form a liquid to a solid, and heat is released.

5) An assumption of the kinetic theory of gases is that the particles of a gas have

1. little attraction for each other and a significant volume.
2. little attraction for each other and an insignificant volume.
3. strong attraction for each other and a significant volume.
4. Strong attraction for each other and an insignificant volume.

6) Which graph best shows the change in volume of 1 mole of nitrogen gas as pressure increases and temperature remains the constant?

7) What is the total number of electrons needed to completely fill all of the orbitals in an atom's second principal energy level?

1. 16
2. 2
3. 8
4. 4

8) An atom in the excited state can have an electron configuration of

1. 1s²2s²
2. 1s²2p¹
3. 1s²2s²2p²
4. 1s²2s²2p⁶

9)Compared to the charge and mass of a proton and electron has

1. the same charge and a smaller mass.
2. the same charge and the same mass.
3. an opposite charge and a smaller mass.
4. An opposite charge and the same mass.

10) Which nuclear equation represents beta decay

1. . ........................................

   27			4			30			1
   	Al	+		He	-->		P	+		N
   13			2			15			9

2. .........................................

   238			234			4
   	U	-->		Th	+		He
   92			90			2

3. . .......................................

   14			14			0
   	C	-->		N	+		e
   6			7			-1

4. ........................................

   37			0			37
   	Ar	+		e	-->		Cl
   18			-1			18

11) What is the total number of sublevels in the fourth principal energy level?

1. 1
2. 2
3. 3
4. 4

12) Which atom in the ground state has only on unpaired electron in its valence?

1. aluminum
2. silicon
3. phosphorous
4. sulfur

13) Which electron dot symbol represents the atom in Period 4 with the highest first ionization energy?

14) Which of these elements in Period 3 has the least tendency to attract electrons?

1. Mg
2. Al
3. S
4. CL

15)Which terms describe a substance that has a low melting point and poor electrical conductivity?

1. covalent and metallic
2. covalent and molecular
3. ionic and molecular
4. ionic and metallic

16) Which chemical formula is both an empirical formula and a molecular formula?

1. CH₄
2. C₂H₆
3. CH₃COOH
4. CH₃CH₂COOCH₃

17) How many grams of sodium are represented by the symbol Na?

1. 1.0 g of NA
2. 10 g of NA
3. 11 g of NA
4. 23 g of NA

18) The shape and bonding in a diatonic bromine molecule are best described as

1. symmetrical and polar
2. symmetrical and nonpolar
3. asymmetrical and polar
4. asymmetrical and nonpolar

19) What is the total number of moles of hydrogen atoms contained in one mole of (NH₄)₂C₂O₄ ?

1. 6
2. 2
3. 8
4. 4

20) Which element at STP is a poor conductor of electricity and has a relatively high electronegativity?

1. Cu
2. S
3. Mg
4. Fe

21) The element arsenic (As) has the properties of

1. metals,only
2. nonmetals, only
3. both metals and nonmetals
4. neither metals nor nonmetals

22) The elements calcium and strontium have similar chemical properties because they both have the same

1. atomic number
2. mass number
3. number of valence electrons
4. number of completely filled sublevels

23) Which element is malleable and ductile?

1. S
2. Si
3. Ge
4. Au

24) Which gas is nonatomic at STP?

1. nitrogen
2. neon
3. fluorine
4. chlorine

25) Which physical characteristic of a solution may indicate the presence of a transition element?

1. its density
2. its color
3. its effect on litmus
4. its effect on phenolphthalein

26) The observed regularities in the properties of elements are periodic functions of their

1. atomic numbers.
2. mass numbers.
3. oxidation states.
4. nonvalence electrons.

27) Given

4NH₃ + 5O₂ --> 4NO+6H₂O

What is the maximum number of moles of H₂O that can be produced when 2.0 moles of NH₃ are completely reacted?

1. 1.0
2. 2.0
3. 3.0
4. 6.0

28)A compound has an empirical formula of HCO2 and a molecular mass of 90 grams per mole. What is the molecular formula of this compound?

1. HCO
2. H₂C₂O₄
3. H₄C₄O₈
4. H₆C₆O₁₂

29)What is the volume occupied by 2.00 moles of AR(g) at STP?

1. 22.4 L
2. 44.8 L
3. 89.6 L
4. 179 L

30) What is the percent by mass of water present in 1.0 mole CaSO₄ * 2H₂O?

1. 10 %
2. 12 %.
3. 21 %
4. 79 %

* = a dot

31) How many grams of KCl must be dissolved in 200 grams of water to make a saturated solution at 60^o C?

1. 30 g
2. 45 g
3. 56 g
4. 90 g

32) Based on Reference Table G, which compound forms spontaneously under standard conditions?

1. NaCl
2. HI
3. C₂H₄
4. NO₂

33) Given the reaction:

A(s) +B(aq) --> C(aq) + D(s)

Which change would increase the rate of this reaction?

1. a decrease in pressure.
2. An increase in pressure.
3. a decrease in temperature.
4. An increase in temperature.

34) When a catalyst is added to a system at equilibrium, a decrease occurs in the

1. heat of the reaction.
2. activation energy.
3. potential energy of the reactants.
4. Potential energy of the products.

35) Which reactions result in an increase in entropy?

1. CO₂(g) --> CO₂(s)
2. H₂O(l) --> H₂O(s)
3. Ca(s) + 2H₂O(l) --> Ca(OH)₂(aq) + H₂(g)
4. NaCl(aq) + AgNO₃(aq) --> AgCl(s) + NaNO₃(aq)

36)Given the reaction at equilibrium:

X₃Y₂(s) <--> 3X²⁺(aq) + 2Y^3-(aq)

What is the correct solubility product (K_sp) for this reaction?

1. K_sp = [X²⁺]³[Y^3-]²
2. K_sp = [X²⁺]³+ 2[Y^3-]²
3. K_sp = 3[X²⁺]2[Y^3-]
4. K_sp = 3[X²⁺] + 2[Y^3-]

37) Which of the following Bronsted bases has the strongest conjugate acid?

1. OH^-
2. F^-
3. HS^-
4. NO₃^-

38) Which compound is salt?

1. NaPO₄
2. H₃PO₄
3. CH₃COOH
4. Ca(OH)₂

39) At 1 atm and 298 K, which of the K_a values listed below represents the strongest acid?

1. 1.1 x 10^-7
2. 1.8 x 10^-5
3. 5.6 x 10^-11
4. 4.6 x 10^-4

40) Which compound will conduct an electric current when dissolved in water?

1. NaOH
2. C₂H₅OH
3. C₆H₁₂O₆
4. C₁₂H₂₂O₁₁

41) according to the Arrhenius theory of acids, citric acid in oranges and acetic acid in vinegar are classified as acids because their aqueous solutions contain

1. hydrogen ions.
2. hydrogen atoms.
3. hydroxide ions.
4. Hydroxide atoms.

42) If 20. milliliters of a 1.0 M solution of HCl is exactly neutralized by 40. Milliliters of NaOH, the molarity of the NaOH solution is

1. 1.0 M
2. 2.0 M
3. 0.50 M
4. 4.0 M

43) Given the reaction:

CH₃COOH(aq) + H₂O(l) <--> CH₃COO^-(aq) + H₃O⁺(aq)

In this reaction, which substances are Bronsted-Lowry bases?

1. CH₃COOH(aq) and H₂O(l)
2. CH₃COOH(aq) and CH₃COO^-(aq)
3. H₂O(l) and H₃O⁺(aq)
4. H₂O(l) and CH₃COO^->(aq)

44) What is the oxidation number of sulfur in H₂SO₄ ?

1. 0
2. -2
3. +6
4. +4

45) Given the unbalanced equation:

__Br₂ + __Sn --> __Br^- + Sn²⁺

When the equation is correctly balanced using the smallest whole number coefficients, the coefficient of Br^- is

1. 1
2. 2
3. 3
4. 4

46) Given the redox reaction in an electrochemical cell:

Ni(s) + Pb²⁺(aq) <--> Ni²⁺(aq) + Pb(s)

A salt bridge is used to connect

1. Ni(s) and Pb(s)
2. Pb²⁺(aq) and Ni²⁺(aq)
3. Ni(s) and Ni²⁺(aq)
4. Pb²⁺(aq) and Pb(s)

47) Which half-reaction correctly presents oxidation?

1. Sn²⁺ + 2e^- --> Sn^o
2. Sn⁴⁺ + 2e^- --> Sn²⁺
3. Sn²⁺ --> Sn^o + 2e^-
4. Sn²⁺ --> Sn⁴⁺ + 2e^-

48) In a redox reaction, the reducing agent will

1. lose electrons and be reduced.
2. lose electrons and be oxidized.
3. gain electrons and be reduced.
4. Gain electrons and be oxidized.

49) Which element is present in all organic compounds?

1. hydrogen.
2. nitrogen..
3. oxygen.
4. carbon.

50) Which products are obtained when CH₄(g) burns completely in an excess of oxygen?

1. CO and H₂O
2. CO and C
3. CO₂ and H₂O
4. CO₂ and CO

51) Which hydrocarbon is a member of the Alkene series?

1. C₂H₂
2. C₃H₆
3. C₄H₁₀
4. C₅H₁₂

52) Which formula represent butane?

1. CH₃CH₃
2. CH₃CH₂CH₃
3. CH₃CH₂CH₂CH₃
4. CH₃CH₂CH₂CH₂CH₃

53) A hydrocarbon molecule is considered to be saturated if the molecule contains

1. single covalent bonds, only.
2. a double covalent bond, only.
3. a triple covalent bond.
4. single and double covalent bonds

54) In a chemical reaction, as a species is oxidized, its oxidation number

1. decreases.
2. increases.
3. remains the same.

55) Given the reaction:

Zn(s) + HCl(aq) --> ZnCl₂(aq) + H₂(g)

As the concentration of the HCl(aq) decreases at constant temperature, the rate of the reaction

1. decreases.
2. Increases
3. Remains the same.

56) As a chemical bond forms between two hydrogen atoms in a system, energy is released , and the stability of the system

1. decreases.
2. Increases
3. Remains the same.