Chemical Reactions Test Period 1
Chemical Reactions
Questions and Answers
- 1.
When bonds break and rearrange to form new chemicals it is called a......
- A.
Physical Change
- B.
Law of Proportions
- C.
Chemical Reaction
- D.
Chemical Property
Correct Answer
C. Chemical ReactionExplanation
A chemical reaction occurs when bonds between atoms are broken and rearranged to form new chemicals. This process involves a change in the chemical composition of the substances involved, resulting in the formation of different molecules or compounds. Unlike a physical change, which only affects the physical properties of a substance (such as its shape or state), a chemical reaction involves a transformation at the molecular level. Therefore, the correct answer is Chemical Reaction.Rate this question:
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- 2.
What is the difference between a physical change and a chemical reaction?
- A.
In a chemical recation new atoms are formed
- B.
In a chemical change bonds are broken and atoms are rearranged
- C.
In a physical change atoms are lost
- D.
In a physical change bonds are broken but in a chemical reaction they are not broken
Correct Answer
B. In a chemical change bonds are broken and atoms are rearrangedExplanation
In a chemical change, bonds between atoms are broken and new bonds are formed, resulting in the rearrangement of atoms to form new substances. This is different from a physical change where the arrangement of atoms remains the same and no new substances are formed. The statement correctly explains that in a chemical change, bonds are broken and atoms are rearranged, highlighting the key difference between a physical change and a chemical reaction.Rate this question:
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- 3.
Type in the coefecients separated by a comma and include the coeffecient "1". for example 1,2,5,2,1 would be the answer for Al + 2N2 + 5O2 => 2N2O5 + AlBalance this chemical reaction ___H2 + ___O2 => ___H2O
Correct Answer
2,1,2 - 4.
Type in the coefecients separated by a comma and include the coeffecient "1". for example 1,2,5,2,1 would be the answer for Al + 2N2 + 5O2 => 2N2O5 + AlBalance this chemical reaction ___C3H8 + ___O2 => ___CO2 + ___H2O
Correct Answer
1,5,3,4Explanation
C 3 C 1,3
H 8 H 8
O 2,10 O 10Rate this question:
- 5.
Type in the coefecients separated by a comma and include the coeffecient "1". for example 1,2,5,2,1 would be the answer for Al + 2N2 + 5O2 => 2N2O5 + AlBalance this chemical reaction ___Al(OH)3 + ___H2SO4 => ___Al2(SO4)3 + ___H2O
Correct Answer
2,3,1,6Explanation
Al 1,2 Al 2
O 7,10,18 O 13,16,18
H 8,12 H 2,8,12
S 1,3 S 3Rate this question:
- 6.
Why do chemist need to work with balanced equations?
- A.
Because of the law of conservation of energy
- B.
Because they just want to
- C.
Because of the law of conservation of mass
- D.
Because they need to get fast reaction rates
Correct Answer
C. Because of the law of conservation of massExplanation
Chemists need to work with balanced equations because of the law of conservation of mass. This law states that matter cannot be created or destroyed in a chemical reaction, only rearranged. Balanced equations ensure that the number of atoms of each element on both sides of the equation is the same, thus demonstrating the conservation of mass. By working with balanced equations, chemists can accurately calculate the amounts of reactants and products involved in a reaction and predict the outcome of chemical reactions.Rate this question:
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- 7.
The heaters in Army MRE's use a heater that give of heat when water is added. This makes the food hot and scrumptious!! What type of reaction is involved?
- A.
Endothermic
- B.
Exothermic
Correct Answer
B. ExothermicExplanation
The given correct answer is "exothermic." This means that the reaction releases heat energy into its surroundings. In the case of the heaters in Army MRE's, when water is added to the heater, a chemical reaction occurs that produces heat. This heat is then transferred to the food, making it hot and delicious.Rate this question:
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- 8.
At the 20 second mark of this experiment a magical reaction happens....what type is it?
- A.
Endothermic
- B.
Exothermic
Correct Answer
A. EndothermicExplanation
At the 20-second mark of the experiment, a magical reaction occurs. Based on the given options, the correct answer is "endothermic." This means that the reaction absorbs heat from its surroundings. In an endothermic reaction, the energy of the products is higher than the energy of the reactants, resulting in a decrease in temperature. Therefore, at the 20-second mark, the reaction is likely absorbing heat, indicating an endothermic process.Rate this question:
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- 9.
What type of reaction is this? C10H22 + O2 => CO2 + H2O
- A.
Synthesis
- B.
Decomposition
- C.
Combustion
- D.
Single Replacement
- E.
Double Replacement
Correct Answer
C. CombustionExplanation
The given chemical equation represents the combustion of C10H22 (a hydrocarbon) with oxygen (O2) to produce carbon dioxide (CO2) and water (H2O). Combustion reactions involve the rapid combination of a fuel (in this case, C10H22) with oxygen, resulting in the release of energy in the form of heat and light. Therefore, the correct answer is combustion.Rate this question:
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- 10.
What type of reaction is this? KOH + HBr => KBr + H2O
- A.
Synthesis
- B.
Decomposition
- C.
Combustion
- D.
Single Replacement
- E.
Double Replacement
Correct Answer
E. Double ReplacementExplanation
This reaction is a double replacement reaction because the cations (K+ and H+) and the anions (OH- and Br-) in the reactants switch places to form new compounds (KBr and H2O) in the products.Rate this question:
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- 11.
What type of reaction is this? N2 + H2 => NH3
- A.
Synthesis
- B.
Decomposition
- C.
Combustion
- D.
Single Replacement
- E.
Double Replacement
Correct Answer
A. SynthesisExplanation
The given reaction is a synthesis reaction because it involves the combination of two reactants (N2 and H2) to form a single product (NH3). In a synthesis reaction, two or more substances combine to form a more complex substance.Rate this question:
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- 12.
What type of reaction is this? Al(OH)3 + HBr => AlBr3 + H2O
- A.
Synthesis
- B.
Decomposition
- C.
Combustion
- D.
Single Replacement
- E.
Double Replacement
Correct Answer
E. Double ReplacementExplanation
This reaction is a double replacement reaction because the cations and anions in the reactants switch places to form new compounds. In this case, the aluminum hydroxide (Al(OH)3) reacts with hydrogen bromide (HBr) to form aluminum bromide (AlBr3) and water (H2O).Rate this question:
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- 13.
What type of reaction is this? Li + H2O => LiOH + H2
- A.
Synthesis
- B.
Decomposition
- C.
Combustion
- D.
Single Replacement
- E.
Double Replacement
Correct Answer
D. Single ReplacementExplanation
In this reaction, lithium (Li) replaces hydrogen (H) in water (H2O) to form lithium hydroxide (LiOH) and hydrogen gas (H2). This is a single replacement reaction because one element (Li) replaces another element (H) in a compound (H2O).Rate this question:
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- 14.
What type of reaction is this?
- A.
Synthesis
- B.
Decomposition
- C.
Combustion
- D.
Single Replacement
- E.
Double Replacement
Correct Answer
B. DecompositionExplanation
This is a decomposition because the image shows a larger substance being broken down into smaller substancesRate this question:
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- 15.
After 400 seconds of this experiment there is less small chips remaining than there is large chips. This demonstrates _____________ effect on reaction rate
- A.
Temperature
- B.
Surface Area
- C.
Pressure
- D.
Using a Catalyst
Correct Answer
B. Surface AreaExplanation
The answer is surface area because a substance broken down into smaller chips would have a greater surface area making the reaction happen fasterRate this question:
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- 16.
At a higher concentration the recation rate is faster and form a greater amount of ___________ in a shorter period of time
- A.
Products
- B.
Reagents (this means reactants)
Correct Answer
A. ProductsExplanation
At a higher concentration, the reaction rate is faster because there are more reactant particles present, leading to more frequent collisions between them. This results in a greater amount of products being formed in a shorter period of time.Rate this question:
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- 17.
In order to increase the reaction rate you can increase all of the following EXCEPT.....
- A.
Temperature
- B.
Concentration
- C.
Pressure
- D.
Surface Area
Correct Answer
C. PressureExplanation
you must DECREASE the pressure in order to increase the reaction rate. This is because decreasing the pressure will allow for the particles to move faster and contact each other more oftenRate this question:
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- 18.
Using what you know about how temperature affects reaction rateswhat is the temperature of the middle beaker?
- A.
Colder than the other twobeakers
- B.
Hotter than the other two beakers
Correct Answer
A. Colder than the other twobeakersExplanation
It is colder than the other two because the reaction is happening at a slower rateRate this question:
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- 19.
Using knowledge from the lab experiment and what we learned about reaction rates how could you get alka seltzer to dissolve the fastes so you could get the medicine in your body the fastest
- A.
Use a whole tablet in cold water
- B.
Use a crushed tablet in room temperature water
- C.
Use a crushed tablet in warm water
- D.
Use a whole tablet in warm water
Correct Answer
C. Use a crushed tablet in warm waterExplanation
Using a crushed tablet in warm water would result in the fastest dissolution of Alka Seltzer. Crushing the tablet increases the surface area, allowing for more contact between the water and the tablet, which speeds up the dissolution process. Warm water also increases the kinetic energy of the water molecules, causing them to move more quickly and collide with the tablet more frequently. This increased collision rate further enhances the dissolution rate. Therefore, using a crushed tablet in warm water would maximize the rate of dissolution and enable the medicine to enter the body more quickly.Rate this question:
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- 20.
If you put a whole tablet of alka seltzer in the same temperature water at the beach in florida and also on top of a mountain in colorado which one would dissolve first?
- A.
Florida
- B.
Colorado
Correct Answer
B. ColoradoExplanation
Colorado because the pressuere would be lessRate this question:
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Current Version
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Mar 21, 2023Quiz Edited by
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Feb 10, 2011Quiz Created by
Chip_brand
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