Deanne and Bo conduct an experiment at school. They put vinegar into a dish, and then they add baking soda to it. Lots of bubbles form as they stir the two substances together. After the bubbling stops, they notice that they no longer smell the distinctive odor of vinegar. Their teacher explains that the atoms making the vinegar and the atoms making the baking soda were recombined to form water, carbon dioxide, and another compound called sodium acetate.(2 points)
a. Deanne and Bo determine that a reaction
did
take place. When a reaction takes place, atoms must
rearrange to form new substance
.
Question 2
b. Which of the following pieces of evidence helped Deanne and Bo answer question a?(2 points)
evidence that was useful to Deanne and Bo evidence that was not observed or was not useful
A solid dissolved in a liquid.
evidence that was useful to Deanne and Bo – A solid dissolved in a liquid.
evidence that was not observed or was not useful – A solid dissolved in a liquid.
A new gas was formed.
evidence that was useful to Deanne and Bo – A new gas was formed.
evidence that was not observed or was not useful – A new gas was formed.
An odor changed.
evidence that was useful to Deanne and Bo – An odor changed.
evidence that was not observed or was not useful – An odor changed.
They saw a new color.
evidence that was useful to Deanne and Bo – They saw a new color.
evidence that was not observed or was not useful – They saw a new color.
Is Nylon shorts synthetic materials or natural materials
evidence that was useful to Deanne and Bo – A new gas was formed.
evidence that was useful to Deanne and Bo – An odor changed.
what about was not helpful
evidence that was not observed or was not useful – A solid dissolved in a liquid.
evidence that was not observed or was not useful – They saw a new color.
Hydrogen peroxide undergoes a decomposition reaction to form water and oxygen gas.
a. The boiling point of water is 100o
C. The boiling point of hydrogen peroxide is about 150o
C. Does this make sense? Why or why not.
(1 point)
Responses
Yes, it makes sense, because a physical change took place.
Yes, it makes sense, because a physical change took place.
Yes, it makes sense, because we expect products and reactants to have different properties.
Yes, it makes sense, because we expect products and reactants to have different properties.
No, it doesn't make sense, because a physical change took place.
No, it doesn't make sense, because a physical change took place.
No, it doesn't make sense, because we expect products and reactants to have different properties.
No, it doesn't make sense, because we expect products and reactants to have different properties.
Question 2
b. How would you expect the density of water to compare to the density of hydrogen peroxide?(1 point)
Responses
The density of water would be the same as the density of hydrogen peroxide.
The density of water would be the same as the density of hydrogen peroxide.
The density of water would be different from the density of hydrogen peroxide.
The density of water would be different from the density of hydrogen peroxide.
It is impossible to tell if the densities would be the same or different.
Yes, it makes sense, because we expect products and reactants to have different properties.
The density of water would be different from the density of hydrogen peroxide.
Aria and Marcus know that when sugar burns, it undergoes this reaction. However, they are not sure how much water is produced. Their teacher encourages them to think about the law of conservation of matter.
C6
H12
O6
+ 6O2
→ 6CO2
+ some amount of H2
O
a. There are 12 atoms of hydrogen shown on the reactant side. How many total atoms of hydrogen must be on the product side?
(1 point)
Responses
2
2
6
6
12
12
18
18
Question 2
b. What does the law of conservation of matter (or the law of conservation of mass) tell the students?(1 point)
Responses
Matter is always gained or lost in a chemical or physical process.
Matter is always gained or lost in a chemical or physical process.
Matter is never gained or lost in a chemical or physical process.
Matter is never gained or lost in a chemical or physical process.
Matter might be lost in a chemical or physical process.
Matter might be lost in a chemical or physical process.
Matter might be gained in a chemical or physical process.
Matter might be gained in a chemical or physical process.
Question 3
c. Aria and Marcus combine 180 grams of sugar with 192 grams of oxygen gas. What would they expect the total mass of the products to be? Why?
You can use the calculator (below the answers) if desired.
(1 point)
Responses
The total mass of the products would be greater than 372 grams, because water is really heavy.
The total mass of the products would be greater than 372 grams, because water is really heavy.
The total mass of the products would be something less than 372 grams, because some of the mass burned into nothing.
The total mass of the products would be something less than 372 grams, because some of the mass burned into nothing.
The total mass of the products would equal 180 grams, because the mass of oxygen gas doesn't make a difference.
The total mass of the products would equal 180 grams, because the mass of oxygen gas doesn't make a difference.
The total mass of the products would be 372 grams, because mass cannot be gained or lost in the process.
The total mass of the products would be 372 grams, because mass cannot be gained or lost in the process.