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Study Guide-LOCOM


Online Study Guide
Instructions
1) You do not need to type in your name in the space in the top-left area above. The results of this study guide will not be sent to your teacher.
2) Carefully read each question and all the answer choices.
3) Select the correct letter from the drop-down feature to the left of each question.
4) When you are finished, click the “Check Your Work” button in the bottom-left corner of the page.
5) The software will grade your work, and then it will show you the results. Note that the correct answer will be displayed beneath the questions.
6) Keep doing the study guide over until you earn a 100 on it.
 

 1. 
The reaction below shows potassium (K) reacting with oxygen (O2) to form potassium oxide. (KO2). The mass of potassium is 39 grams and the mass of oxygen is 32 grams.
K + O2 mc001-1.jpg KO2
What is the mass of potassium oxide from this equation?
a.
39 grams
b.
142 grams
c.
71 grams
 

 2. 

A student observed the following chemical reaction.
Nitrogen (N) + Hydrogen (H) yields Ammonia (NH3)
Select the balanced equation below that correctly represents this reaction.
a.
N2 + H2  mc002-1.jpg  NH3
b.
N2 + 3H2 mc002-2.jpg2NH3
c.
3N2 + H2 mc002-3.jpg3NH2
 

 3. 
An iron block had an initial mass of 100 grams. As the block rusted, its mass increased to 105 grams. The appears to be a violation of the law of conservation of mass, but it is not.
Which choice below best explains why the mass increased?
a.
Water is absorbed as rust forms on the iron block.
b.
Oxygen combines with iron when rust is formed.
c.
Rust releases heat and makes the iron expand.
 

 4. 
A scientist wants to study what happens when carbon dioxide CO2 reacts with hydrogen H2.  The scientist discovers that this reaction produces methane CH4 and water H2O.
Which equation correctly represents this reaction?
a.
CO2  +  H2   mc004-1.jpg  CH4 + H2O
b.
CO2  +  4H2   mc004-2.jpg  CH4 + 2H2O
c.
CO2  +  4H2   mc004-3.jpg  CH4 + H2O
 

 5. 
A student adds 5 grams of baking soda to 50 grams of vinegar in a container and quickly attaches a balloon to the top of the bottle. The students investigation is shown below.
mc005-1.jpg
What occurred in this investigation?
a.
The reaction in the container produces gas, which causes the balloon to inflate.
b.
The reaction produces heat, which causes the balloon to soften and change shape.
c.
The outside air pressure pushes on the container and forces air inside the balloon.
 

 6. 
A student wants to study what happens when sulfur (S) reacts with ozone (O3) H2.  The student discovers that this reaction produces sulfur dioxide. 
Which of the following equations correctly represents this reaction?
a.
3S +2O3 mc006-1.jpg SO
b.
S + 2O3 mc006-2.jpg 3SO2
c.
3S +2O3 mc006-3.jpg 3SO2
 

 7. 
In the chemical reaction shown below, 32 grams of ammonia (NH3) have been produced. .
mc007-1.jpg
If the hydrogen (H2) was 20 grams, what is the mass of the nitrogen (N2)?
a.
32 grams
b.
12 grams
c.
10 grams
 

 8. 
The law of conservation of mass states that no atoms are created or destroyed during reactions.
mc008-1.jpg
Which equation best represents the law of conservation of mass?
a.
mc008-2.jpg
b.
mc008-3.jpg
c.
mc008-4.jpg
 

 9. 
The law of conservation of mass states that no mass is created or destroyed during reactions.
Which procedure best represents the law of conservation of mass?
a.
combining 2g of copper &  4g of sulfur to produce 6g of copper sulfate
b.
using filter paper to separate 2 grams of solid from 10 grams of water
c.
burning 2 kilograms of wood leaves 0.4 kilogram of ash
 

 10. 

Equation Choices
N2 + O2àN2O
N2 + 2O2àN2O
2N2 + O2à2N2O
2N2 + 2O2à2N2O
Which equation best represents the law of conservation of mass?
a.
N2 + O2àN2O
b.
N2 + 2O2àN2O
c.
2N2 + O2à2N2O
 



 
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