Gen Chem Final Exam Review

Heat Energy Problems

100

Identify the following as either a chemical change or physical change: 

- Burning a log in a fireplace 

- Starting a car on fire 

- Blending fruit to make a smoothie 

- Digesting your lunch 

chemical 

chemical 

physical 

chemical

200

What are the reactants and products present in a combustion reaction?

Reactants: carbon containing compound and oxygen Products: carbon dioxide and water 

** heat energy is both a reactant and product 

300

How many joules of heat are needed to raise the temperature of 10.0g of aluminum from 22^oC to 55^oC, if the specific heat of aluminum is 0.90 J/g^oC

297 J

400

A 15.75-g piece of iron absorbs 1086.75 joules of heat energy, and its temperature changes from 25°C to 175°C.  Calculate the specific heat capacity of iron.

0.46 J/gC^o

500

To what temperature will a 50.0 g piece of glass raise if it absorbs 5275 joules of heat and its specific heat capacity is 0.50 J/g°C?  The initial temperature of the glass is 20.0°C.

T_f = 231^oC

pH and pKa

100

Acetic acid has a Ka of 1.8 x 10^-5 while formic acid has a Ka of 3.8 x 10^-5. Which acid is a stronger acid? 

formic acid 

200

Calculate the pH of a solution with an [OH-] of 8.2 x 10^-6 M

pH = 8.9

300

Calculate the pH of a solution with an [H⁺] of 1.0 x 10^-2

pH = 2

400

Find the [H⁺] of a solution with a pH of 3.3

5.0 x 10^-4 

500

Find the [OH^-] of a solution with a pH of 10.2 

1.58 x 10^-4

Ionic and Molecular Compounds

100

Determine the number of protons, neutrons, and electrons in ⁵⁸N²⁺

28 protons, 30 neutrons, 26 electrons

200

Write the chemical formula for iron(III) oxide

Fe₂O₃

300

Write the name chemical formula of a compound made between sodium and nitrogen 

Na₃N, sodium nitride 

*** ionic compounds end in the suffix -ide

400

What is the electron geometry and bond angles of SCl₂?

tetrahedral, 109.5^o

500

Which of the following bonds are polar covalent?

P-Cl, Br-Br, I-O, Na-F

P-Cl

I-O

Chemical Reactions

100

Classify the following reaction: 

AgNO3 + NaCl > AgCl + NaNO3

double replacement (metathesis)

200

Balance the following chemical equation: 

H₃PO₄ + KOH > K₃PO₄ + H₂O

1 H₃PO₄ + 3 KOH > 1 K₃PO₄ + 3 H₂O

300

Which species is oxidized and which is reduced in the following reaction? 

2 H2(g) + O2(g) >? 2 H2O(l)

H2 - oxidized 

O2 - reduced 

400

Which species is oxidized and which is reduced in the following reaction? 

As2O3 + MnO3 >? H3AsO4 + Mn2+

As2O3 - oxidized 

MnO3 - reduced 

500

Write a balanced chemical equation for the reaction that occurs between CuCO3(s) and H2SO4(aq)

CuCO3(s) and H2SO4(aq) > CuSO4(aq) + CO2(g) + H2O(l)

Random

100

What is the Ka expression of the following chemical equation? 

H3PO4 (aq) + Ca(OH)2 (aq) → Ca3(PO4)2 (s) + H2O (l)

[H₃PO₄][Ca(OH)₂] = Ka

200

How many grams of K₂CO₃ are needed to make a 200 mL solution with a molarity of 2.5M?

70g

300

At 40oC, the solubility of KBr is 80g per 100g of water. If 75g of KBr is added to 180g of water, is this solution saturated or unsaturated?

unsaturated

400

What is the [H3O+] of a solution if the [OH-] is 4.5 x 10-5? Is this solution acidic or basic?

2.22 x 10^-10, basic

500

Will reactants or products be favored at equilibrium? 

HNO₃ (aq) + H₂O (l) > H₃O⁺ (aq) + NO₃^_  (aq)

(hint: you will need to look at the acid/base strength chart in your notes)

products will be favored