Exam 3 Review Fall 23

Chapter 8

100

What is the equation and units for osmolarity?

Osmolarity= molarity x i

Units: osmol

200

Calculate the percent by mass concentration of a solution with 23.4g solute in 86.1g solution.

27.2%

300

Calculate the molarity of 20.0 g NaCl in 1.00 L of solution.

0.342 mol/L

400

Calculate the volume percent of solute: 4.00 mL of bromine in enough carbon tetrachloride to give 87.0 mL of solution.

4.60%

500

How many grams of Na₂CO₃ are needed to prepare 25.0 mL of a 2.00%(m/v) Na₂CO₃ solution?

0.500 g

Chapter 9

100

What type of reaction is this: 2CuO → 2Cu + O₂

decomposition

200

What is the oxidation number of O₂?

0

300

Oxidation number of N in: NH₂OH

-1

400

Which substance is reduced in the following redox reaction? CO + H₂O → CO₂ + H₂

H₂O

500

What is the equilibrium expression for the equation SnO₂(s) + 2CO(g) <==> Sn(s) + 2CO₂(g)?

K_eq= [CO₂]²/[CO]²

Chapter 10

100

Is NH₃ a Bronsted-Lowry acid or base?

Base (No acidic H⁺ and has a lone pair)

200

What is the [H₃O⁺] in a solution with [OH^-]=1x10^-12M?

1x10^-2M

300

What is the pH of a solution with [OH^-]=1x10^-4 M

10.0

400

What is the conjugate base of HClO₃?

ClO₃^-

500

What is the pH when [OH^-]=3.42 x 10^-5?

9.53

Concepts/Definitions

100

Explain to me what the oxidizing agent is and whether it loses or gains electrons.

Oxidizing agent is the substance reduced, it gains electrons from the substance oxidized

200

A solution where more particles are dissolved than listed on the solubility chart

Supersaturated solution

300

According to Le Chatelier's principle: when a reactant concentration is decreased, the reaction will shift ____

left (toward reactants)

400

List three factors that influence chemical reaction rates

Presence of catalysts

Temperature

State of subdivision

Pressure

500

According to Le Chatelier's principle, if pressure increases, the reaction will shift toward the side with _______

The least number of moles

Feeling lucky?

100

Is NaCl soluble in water?

Yes

200

What type of reaction is this: C₃H₈ + 5O₂ → 3CO₂ + 4H₂O

combustion

300

Is SO₃ + H₂O → H₂SO₄ a redox reaction?

No, why?

400

In an osmolarity problem, what is the value of i for glucose?

1

500

For the reaction N₂O₄(g) <==> 2NO₂(g), Keq = 0.2. At a particular time, the following concentrations are measured: [N₂O₄]=2.0 M, [NO₂] = 0.2 M. Is this reaction at equilibrium? If not which direction will the reaction proceed?

K_eq=[NO₂]²/[N₂O₄] = (0.2)²/2.0 = 0.02 No, reaction will proceed right, because there is less product than Keq