Chemistry Review

Bonding (Intermolecular Forces)

100

The unusually high boiling point of water is due to the : (1) network bonds between the molecules (2) hydrogen bonds between the molecules (3) linear structure of the molecules (4) nonpolar character of the molecules

(2) hydrogen bonds between the molecules

200

A valid Lewis structure of __ cannot be drawn without violating the octet rule : (1) (PO4)-3 (2) PF3 (3) CCl4 (4) SeF4 (5) NF3

(4) SeF4

300

Of the possible bonds between carbon atoms (single, double, triple), ______ : (1) a triple bond is longer than a single bond (2) a double bond is stronger than a triple bond (3) a single bond is stronger than a triple bond (4) a double bond is longer than a triple bond

(4) a double bond is longer than a triple bond

400

How many equivalent resonance forms can be drawn for SO2, SO3, and (SO3) -2 without violating the octet rule?

SO2 --> 2 resonance structure (SO3)-2 --> 2 resonance structure SO3 --> 1 resonance structure

500

Given : NaCl + NH3 +CO2 + H2O --> NaHCO3 + NH4Cl : Write the chemical formula for one compound in the equation that contains both ionic bonds and covalent bonds. Draw the Lewis electron-dot diagram for the reactant containing nitrogen in the equation.

- NaHCO3 --> (Na+) ionic bond with (HCO3-) l (contain a covalent bond between hydrogen, carbon, and oxygen) or - NH4Cl --> (NH+) ionic bond with (Cl-) l (contain covalent bond between nitrogen and hydrogen) Lewis-dot diagram: :N-H-H-H

Kinetics and Equilibrium

100

Which reaction system tends to become less random as the reactants form products? : (1) C(s) + O2(g) --> CO2(g) (2) S(s) + O2(g) --> SO2(g) (3) I2(s) + Cl2(g) --> 2ICl(g) (4) 2Mg(s) + O2(g) --> 2MgO(s)

(4) 2Mg(s) + O2(g) --> 2MgO(s) b/c the question is asking for the situation with the least entropy, we are looking for a phase in where the molecules of the product is less disorder and limited in motion

200

In which reaction will the point of equilibrium shift to the left when the pressure on the system is increased? : (1) C(s) + O2(g) <--> CO2(g) (2) CaCO3(s) <--> CaO(s) + CO2(g) (3) 2Mg(s) + O2(g) <--> 2MgO(s) (4) 2H2(g) + O2(g) <--> 2H2O(g)

(2) CaCO3(s) <--> CaO(s) + CO2(g) * notice that pressure only affect gases * the side with the most mole of gases with decrease as equilibrium is shifted to the opposite side

300

( Potential diagram will be draw on board) Which arrow represent the part of reaction most likely to be changed by the addition of a catalyst? : Which letter represents the activation energy for the reverse reaction? :

- B - D

400

( Potential diagram will be drawn on board) Which potential energy diagram represents the reaction A + B --> C + energy?

- 2

500

Consider the following equation : N2(g) + 3H2(g) <--> 2NH3(g) + heat : Propose changes in concentration, pressure and temperature that would increase the production of NH3

concentration - increase concentration of N2 or H2; pressure - increase pressure; temperature - decrease temperature

Acid and Base

100

Given the diagram representing a reaction : HCl +H2O--> H3O+ + Cl- : According to Bronsted Lowery theory, the water acts as : (1) a base because it accepts an H+ (2) a base because it donates an H+ (3) an acid because it accepts an H+ (4) an acid because it donates an H+

(1) a base because it accepts an H+ * note it is a conjugate base

200

Which indicator would best distinguish between a solution with a pH of 3.5 and a solution with a pH of 5.5? : (1) bromthymol blue (2) bromcresol green (3) litmus (4) thymol blue

(2) bromcresol green * check table M

300

Which compound dissolves in water to form an aqueous solution that can conduct an electric current? : (1) CCl4 (2) C2H5OH (3) CH3COOH (4) CH4

(3) CH3COOH b/c electric currents are caused by substances known as electrolyte when dissolved in water - ionic compounds (salts), acids, and bases

400

How many milliters of 0.20 M H2SO4 are required to completely neutralize 40.mL of 0.10 M Ca(OH)2? :

20 milliters * Table T --> MaVa = MbVb (.20 M)(x) = (.10M)(.40mL)

500

Phosphoric acid is neutralized by a solution of sodium hydroxide. What is the name of the salt formed from the neutralization?

(sodium phosphate) H3PO4 + NaOH --> Na3PO4 + H2O

Organic Chemistry

100

Which general formula represents the compound CH3CH2CCH? : (1) Cn Hn (2) Cn H2n (3) Cn H2n-2 (4) Cn H2n+2

(3) Cn H2n-2 * check table Q - totaling the hydrocarbon to have 4 carbon atoms and 6 hydrogen atoms

200

Please draw the structure of ( 1-propyne)

H-C(triple bond)C-C(bond with three hydrogen)

300

Which two compounds have the same molecular formula but different chemical and physical properties? : (1) CH3CH2Cl and CH3CH2Br (2) CH3CHCH2 and CH3CH2CH3 (3) CH3CHO and CH3COCH3 (4) CH3CH2OH and CH3OCH3

(4) CH3CH2OH and CH3OCH3 b/c both have the same molecular formula-- 2 carbon atoms, 6 hydrogen atoms, 1 oxygen atom-- and each compound have different functions

400

Which nuclides are used to date the remains of a once-living organism? : (1) C-14 and C-12 (2) Co-60 and Co-59 (3) I-131 and Xe-131 (4) U-238 and Pb-206

(1) C-14 and C-12 b/c carbon is found in all organic matter

500

Draw a structural formula for acetamide (CH3CONH3)

(bond with 3 hydrogen)C-C(double bond O on top)-N (bond with 2 hydrogen)

Nuclear Chemistry

100

which equation represents a nuclear reaction that is an example of an artificial transmutation? : (1) 43/21Sc --> 43/20 Ca + 0/1 e (2) 14/7 N + 4/2 He --> 17/8 O + 1/1 H (3) 10/4 Be --> 10/5 B + 0/-1e (4) 14/6 C --> 14/7 N + 0/-1 e

(2) 14/7 N + 4/2 He --> 17/8 O + 1/1 H

200

Which particle is emitted when an atom of 85Kr spontaneously decays? : (1) an alpha particle (2) a beta particle (3) a neutron (4) a proton

(2) a beta particle * check Table N and table O

300

Given the equation: 235/92 U + 1/0 n --> 92/36Kr + 142/56 Ba + 2 1/0 n + energy : Identify the type of nuclear reaction represented by the equation

Nuclear fission -- b/c nucleus of an atom is split into smaller nuclei (or) Transmutation -- b/c the nucleus of one atom is changed into the nucleus of an atom of different element

400

Complete the nuclear equation for the decay of Po-210, by writing a notation for the missing product. : 210/84 Po --> 4/2 He + _______________

206/82 Pb

500

Determine the total mass of an original 28.0-milligram sample of Po-210 that remains unchanged after 414 days.

(3.5 mg) Po-210 half life is 138 days 414/138 = 3 half-life 28 --> 14 --> 7 --> 3.5