Chemical Reactions Test Period 4
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 the conversion of reactants into products, resulting in a change in the chemical composition of the substances involved. Unlike physical changes, which only affect the physical properties of a substance (such as shape, size, or state), chemical reactions involve 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 atoms are rearranged to form new substances. This is different from a physical change where no new substances are formed and atoms are not lost. In a physical change, bonds may be broken, but they are not rearranged to form new substances like in a chemical reaction. Therefore, the correct answer is that in a chemical change, bonds are broken and atoms are rearranged.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. By balancing the equations, chemists ensure that the same number of atoms of each element is present on both sides of the equation, maintaining the mass balance. This allows for accurate calculations and predictions of the amounts of reactants and products involved in a reaction.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." In this context, the heaters in Army MRE's release heat when water is added, resulting in hot and delicious food. This suggests that the reaction involved is exothermic, as it releases heat energy into the surroundings.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 this experiment, a magical reaction occurs. Based on the given options, the correct answer is endothermic. In an endothermic reaction, heat is absorbed from the surroundings, resulting in a decrease in temperature. This suggests that at the 20 second mark, the reaction in the experiment absorbs heat from its surroundings, 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 reaction involves the combustion of C10H22 (a hydrocarbon) with O2 (oxygen) to produce CO2 (carbon dioxide) and H2O (water). Combustion reactions are characterized by the rapid combination of a substance with oxygen, resulting in the release of heat and light. In this case, the hydrocarbon is being oxidized by oxygen to produce carbon dioxide and water, which are the typical products of a combustion reaction. 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-) from the reactants switch partners to form new compounds (KBr and H2O) in the product.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 reaction N2 + H2 => NH3 is a synthesis reaction. In a synthesis reaction, two or more substances combine to form a single, more complex substance. In this case, nitrogen gas (N2) and hydrogen gas (H2) combine to form ammonia (NH3).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 hydrobromic acid (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
This reaction is a single replacement reaction because the lithium (Li) replaces the hydrogen (H) in the water (H2O) to form lithium hydroxide (LiOH) and hydrogen gas (H2). In a single replacement reaction, one element replaces another element in a compound.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 molecules present, leading to more frequent collisions and increased chances of successful reactions. As a result, a greater amount of products is 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 what we learned about reaction rates how could you get alka seltzer to dissolve the fastest 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
The surface area of a substance affects the rate of reaction. When a tablet is crushed, it increases the surface area, allowing more particles to come into contact with the water molecules. This increases the chances of successful collisions and speeds up the dissolution process. Additionally, warm water molecules have more kinetic energy, which enhances the movement of particles and increases the rate of dissolution. Therefore, using a crushed tablet in warm water would provide the largest surface area and the highest temperature, resulting in the fastest dissolution of the alka seltzer tablet and the quickest absorption of the medicine into the body.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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- 21.
Activation energy is the energy needed to get a reaction started. Usually, this is the heat energy of the reactants. If something has a high activation energy, then it is hard to get the reaction to happen unless the temperature is high. If the bond between A-A or B-B is very strong, then the activation energy for the reaction will be
- A.
High
- B.
Low
- C.
The bond strength will not affect the activation energy
Correct Answer
A. HighExplanation
The given correct answer is "High". This is because if the bond between A-A or B-B is very strong, it means that it requires a significant amount of energy to break those bonds and initiate the reaction. Therefore, the activation energy for the reaction will be high.Rate this question:
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- 22.
Would it still be safe drink the milk if you increased the temperature
- A.
Yes....as long as the milk flavor did not start to decrease
- B.
No...it needs to stay this cold
Correct Answer
A. Yes....as long as the milk flavor did not start to decreaseExplanation
Increasing the temperature of milk does not necessarily make it unsafe to drink. However, if the temperature is increased too much, it can lead to the growth of bacteria and spoilage of the milk. The safety of drinking milk depends on factors such as the duration and extent of temperature increase, storage conditions, and the milk's freshness. As long as the milk flavor does not start to decrease, it is likely safe to consume.Rate this question:
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- 23.
If I could not increase the temperature how else could I get these bonds to break?
- A.
Increase the pressure
- B.
Increase the concentration
- C.
Add a catalyst
- D.
Decrease the temperature
Correct Answer
C. Add a catalystExplanation
adding a catalyst would aid in breaking the bonds without changing the reactionRate this question:
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- 24.
Is the formation of product AB likely to occur?
- A.
Yes because the bond strength of AB is strong
- B.
No because the bond strength of the reactants is strong but the strength of the product bond is weak
- C.
Not enough information
- D.
Yes because the bond strength of reactants and products is the same
Correct Answer
B. No because the bond strength of the reactants is strong but the strength of the product bond is weakExplanation
The given answer suggests that the formation of product AB is not likely to occur. This is because while the bond strength of the reactants is strong, the strength of the product bond is weak. This implies that the reactants are more stable in their current form and are unlikely to form the product AB.Rate this question:
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- 25.
Choose the correct reaction below: One molecule of A2 and one of B2 (the reactants), chemically react to form 2 molecules of AB (the products).
- A.
A + A --> A2
- B.
AB --> A + B
- C.
A2 + B2 --> 2AB
- D.
2AB --> A2 + B2
Correct Answer
C. A2 + B2 --> 2ABExplanation
The correct reaction is A2 + B2 --> 2AB because it follows the given information that one molecule of A2 and one molecule of B2 react to form 2 molecules of AB. This reaction shows the correct stoichiometry and product formation.Rate this question:
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Mar 21, 2023Quiz Edited by
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Feb 10, 2011Quiz Created by
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