Balanced Equations
___H2+__O2--->___H2O
___H2+__O2--->___H2O
2H2+(1)O2--->2H2O
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
Endothermic reactions are chemical reactions in which the reactants absorb heat energy from the surroundings to form products.
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
__NaCl2---->___Na+___Cl2
__NaCl2---->___Na+___Cl2
2NaCl---->2Na+(1)Cl2
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
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.
Name 3 ways to change the rate of reaction
catalyst
temperature
surface area
concentration
___HCl+___Na---> ___NaCl +___H2
___HCl+___Na---> ___NaCl +___H2
2HCl+2Na---> 2NaCl +(1)H2
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
What is avogadro's number?
6.022 X 1023 particles/atoms/molecules
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.
___KClO3 → ___KClO4 + ___KCl
___KClO3 → ___KClO4 + ___KCl
4KClO3 → 3KClO4 + (1)KCl
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
Define a catalyst
a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change.
Give an example of a catalyst
(you can use your phone)
enzymes
yeast (lab example)
___CO2 + ___H2O → ___C6H12O6 + ___O2
___CO2 + ___H2O → ___C6H12O6 + ___O2
6CO2 + 6H2O → C6H12O6 + 6O2
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
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.
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).