Exam 3 Review

Lewis Structures & Hybridization

100

How many sigma and pi components are present in a triple bond?

One sigma, two pi

200

What is the hybridization of the central carbon in HCN?

sp

300

What is the hybridization of the central atom in IF₅?

sp³d²

400

True or False:

In the most favorable Lewis structure for HCN, there is 1 single bond, 1 triple bond, and 1 lone pair of electrons.

True.

500

What is the hybridization of the central atom in XeF₂?

sp³d

Writing & Balancing Equations

100

How do you predict the products of a precipitation reaction?

Pair each cation with the opposite anion.

200

What is the sum of the coefficients for the complete combustion of methanol, CH₃OH?

10

300

What is the sum of the coefficients of this balanced equation?

__ Fe + __ Cl₂ ---> __ FeCl₃

7

400

What is the sum of the coefficients for the combustion reaction of C₁₂H₂₄SO₃?

87

500

How much aluminum chloride would be produced using 8.60g of aluminum and 22.0g of chlorine gas in the reaction?

2Al + 3Cl₂ --> 2AlCl₃

27.6g

Limiting Reactants & Percent Yield

100

What is the equation for percent yield?

(actual / theoretical) x 100 = percent yield

200

How do you determine the limiting reactant?

Calculate the mass of product produced by each reactant, the one that produces the least product is the limiting reactant.

OR

Convert each reactant into moles and divide by their respective coefficient.

300

If the percent yield is 85.6% and 150g of product was produced in lab, how much product would be produced by the limiting reactant?

175g

400

When 95.0 grams of C₁₀H₂₂ are completely combusted, 232 grams of CO₂ form. What is the percent yield for this reaction?

2 C₁₀H₂₂ + 31 O₂ --> 20 CO₂ + 22 H₂O

78.9%

500

Which substance is the limiting reactant when 2.0g of sulfur with 3.0g of oxygen and 4.0g of sodium hydroxide?

2 S_(s) + 3 O_2(g) + 4NaOH_(aq) --> 2Na₂SO_4(aq) + 2H₂O(l)

NaOH_(aq)

Molarity & Ionic Equations

100

What does M stand for?

Molarity, or mol/L

200

What is a net ionic equation?

It cancels out spectator ions and only includes the ions involved in the substrate.

300

What volume in mL of 0.250 M Na3PO4 contains 4.95g sodium?

287 mL

400

What is the sum of the coefficients for the complete ionic equation?

HNO_3(aq) + NaOH_(aq) --> H₂O_(l) + NaNO_3(aq)

7

500

What volume in mL of 0.220 M Ba(NO3)2 contains 2.45g nitrogen?

397 mL

Misc.

100

True or False:

The oxidation state of Al in Al(s) is +3

False. 

Al(s) is a free element, so its oxidation state is 0.

200

True or False:

C₂^2- should have a stronger bond than C₂

True

300

True or False:

The flammability of octane is a chemical property.

True

400

Which of the following is NOT a strong acid?

HCl, HF, HBr, HI

HF

500

True or False:

The sigma component of a double bond is generally weaker than the pi component of a double bond.

False