Chemistry B Review

Balanced Equations

100

___H₂+__O₂--->___H₂O

___H₂+__O₂--->___H₂O

2H₂+(1)O₂--->2H₂O

200

__NaCl₂---->___Na+___Cl₂

__NaCl₂---->___Na+___Cl₂

2NaCl---->2Na+(1)Cl₂

300

___HCl+___Na---> ___NaCl +___H₂

___HCl+___Na---> ___NaCl +___H₂

2HCl+2Na---> 2NaCl +(1)H2

400

___KClO₃ → ___KClO₄ + ___KCl

___KClO₃ → ___KClO₄ + ___KCl

4KClO₃ → 3KClO₄ + (1)KCl

500

___CO₂ + ___H₂O → ___C₆H₁₂O₆ + ___O₂

___CO₂ + ___H₂O → ___C₆H₁₂O₆ + ___O₂

6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂

Moles to moles

100

Given the balanced equation representing a reaction:

4Al(s)+3O₂(g)---> 2Al₂O₃(s)

How many moles of Al(s) react completely with 7.50 moles of O₂(g) to produce 5.00 moles of 2Al₂O₃(s)?

A) 2.50 mol

B) 3.50 mol

C) 10.00 mol

D) 6.50 mol

C) 10.00 mol 

7.50 mol O₂ X (4 mol Al / 3 mol O₂) = 10 mol Al

200

2. Given the balanced equation representing the reaction between carbon dioxide and water

in photosynthesis (products = glucose & oxygen):

6CO₂ + 6H₂O --> C₆H₁₂O₆ + 6O₂

According to this equation, what is the mole ratio of CO2 and glucose

(a) 1 g C₆H₁₂O₆/ 6 g CO₂

(b) 6 g C₆H₁₂O₆ / 1 g CO₂ 

(c) 6 mol C₆H₁₂O₆/ 1 mol CO₂

(d) 1 mol C₆H₁₂O₆/ 6 mol CO₂

(d) 1 mol C₆H₁₂O₆/ 6 mol CO₂

300

Refer to problems 1 & 2. 

4Al(s)+3O₂(g)---> 2Al₂O₃(s)

6CO₂ + 6H₂O --> C₆H₁₂O₆ + 6O₂

What type of chemical reactions are present above?

(a) Single replacement & decomposition 

(b) Synthesis & Decomposition

(c) Synthesis & Single Replacement

(d) Decomposition & Double Rep.

(c) Synthesis & Single Replacement

400

What term states that a reaction is most likely to occur when the reactant particles collide with the proper energy & orientation?

(a) Law of Conservation of Mass 

(b) Lewis’ Valence Law

(c) The Collision Theory

(d) Law of Conservation of Energy

(c) The Collision Theory

500

The purpose of a catalyst is to _______ the ______ of the reaction pathway.

(a) Lower/Activation Energy 

(b) Increase/Activation Energy

(c) Increase/Concentration 

(d) Lower/Concentration

(a) Lower/Activation Energy

Definitions

100

Define endothermic

Endothermic reactions are chemical reactions in which the reactants absorb heat energy from the surroundings to form products.

200

Define exothermic

An exothermic reaction is a chemical reaction in which less energy is needed to break bonds in the reactants than is released when new bonds form in the products. During an exothermic reaction, energy is constantly given off, often in the form of heat. All combustion reactions are exothermic reactions.

300

What is avogadro's number?

6.022 X 10²³ particles/atoms/molecules

400

Define a catalyst

a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change.

500

Explain Le Châtelier's principle

Le Châtelier's principle states that if a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium shifts to counteract the change to reestablish an equilibrium.

Misc

100

In terms of collision theory, why does a decrease in temperature result in a decrease in the rate of reaction?

Particles have less energy and therefore move slower

200

Name 3 ways to change the rate of reaction

catalyst

temperature

surface area

concentration 

300

Explain Kinetic Molecular theory

The kinetic-molecular theory explains the states of matter, and is based on the idea that matter is composed of tiny particles that are always in motion. This theory helps explain observable properties and behaviors of solids, liquids, and gases.

400

Give an example of a catalyst

(you can use your phone)

enzymes

yeast (lab example)

500

Given the balance equation representing a reaction:

2NaCl + energy --> 2Na⁺  + Cl₂^-

In this reaction, the energy is (absorbed/released) as bonds in NaCl are (formed/broken).

Given the balance equation representing a reaction:

2NaCl + energy --> 2Na⁺  + Cl₂^-

In this reaction, the energy is (absorbed/released) as bonds in NaCl are (formed/broken).