Analyze Factors Affecting Reaction Rate - Chemistry
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Which change increases rate mainly by increasing the fraction of particles above $E_a$: higher temperature or higher surface area?
Which change increases rate mainly by increasing the fraction of particles above $E_a$: higher temperature or higher surface area?
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Higher temperature. Temperature affects the energy distribution of particles.
Higher temperature. Temperature affects the energy distribution of particles.
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What is the overall effect of increasing surface area of a solid reactant on reaction rate?
What is the overall effect of increasing surface area of a solid reactant on reaction rate?
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Reaction rate increases. More exposed particles available for reaction at the surface.
Reaction rate increases. More exposed particles available for reaction at the surface.
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Choose the word that completes the statement: Increasing temperature makes collisions on average more ____.
Choose the word that completes the statement: Increasing temperature makes collisions on average more ____.
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Energetic. Temperature increases average collision energy.
Energetic. Temperature increases average collision energy.
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What is the overall effect of increasing reactant concentration on reaction rate (solutions/gases)?
What is the overall effect of increasing reactant concentration on reaction rate (solutions/gases)?
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Reaction rate increases. More particles per volume leads to more frequent collisions.
Reaction rate increases. More particles per volume leads to more frequent collisions.
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Identify the best interpretation: If rate increases after adding more reactant to the same volume, which factor caused it?
Identify the best interpretation: If rate increases after adding more reactant to the same volume, which factor caused it?
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Increased concentration. Adding reactant increases concentration in same volume.
Increased concentration. Adding reactant increases concentration in same volume.
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Identify the factor that changes average kinetic energy of particles: temperature, concentration, or surface area.
Identify the factor that changes average kinetic energy of particles: temperature, concentration, or surface area.
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Temperature. Temperature directly affects average kinetic energy of particles.
Temperature. Temperature directly affects average kinetic energy of particles.
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Which change increases rate mainly by increasing the fraction of particles above $E_a$: higher temperature or higher surface area?
Which change increases rate mainly by increasing the fraction of particles above $E_a$: higher temperature or higher surface area?
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Higher temperature. Temperature affects the energy distribution of particles.
Higher temperature. Temperature affects the energy distribution of particles.
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What is activation energy, $E_a$, in the context of reaction rate?
What is activation energy, $E_a$, in the context of reaction rate?
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Minimum energy required for reactant particles to react upon collision. Energy barrier that must be overcome for reaction to occur.
Minimum energy required for reactant particles to react upon collision. Energy barrier that must be overcome for reaction to occur.
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What symbol is commonly used for activation energy in reaction-rate discussions?
What symbol is commonly used for activation energy in reaction-rate discussions?
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$E_a$. Standard symbol for activation energy in kinetics.
$E_a$. Standard symbol for activation energy in kinetics.
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Which change would most likely increase the initial rate: lower concentration or higher temperature?
Which change would most likely increase the initial rate: lower concentration or higher temperature?
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Higher temperature. Temperature has a larger effect on rate than concentration.
Higher temperature. Temperature has a larger effect on rate than concentration.
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Which particle-level change best explains why higher temperature increases reaction rate?
Which particle-level change best explains why higher temperature increases reaction rate?
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A larger fraction of particles has energy $ $ $E_a$. Higher temperature shifts energy distribution to higher energies.
A larger fraction of particles has energy $ $ $E_a$. Higher temperature shifts energy distribution to higher energies.
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Which change would increase rate if reactants are only gases: increasing surface area or increasing pressure?
Which change would increase rate if reactants are only gases: increasing surface area or increasing pressure?
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Increasing pressure. Pressure affects gas concentration; surface area is irrelevant.
Increasing pressure. Pressure affects gas concentration; surface area is irrelevant.
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Identify the factor changed when a solid is ground into smaller pieces: temperature, concentration, or surface area.
Identify the factor changed when a solid is ground into smaller pieces: temperature, concentration, or surface area.
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Surface area increases. Grinding breaks solid into smaller pieces with more surface.
Surface area increases. Grinding breaks solid into smaller pieces with more surface.
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Identify the factor changed when a solution is diluted with water: temperature, concentration, or surface area.
Identify the factor changed when a solution is diluted with water: temperature, concentration, or surface area.
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Concentration decreases. Dilution reduces the number of particles per volume.
Concentration decreases. Dilution reduces the number of particles per volume.
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Identify the factor changed when a reaction mixture is heated: temperature, concentration, or surface area.
Identify the factor changed when a reaction mixture is heated: temperature, concentration, or surface area.
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Temperature increases. Heating increases the average kinetic energy of particles.
Temperature increases. Heating increases the average kinetic energy of particles.
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Identify the best interpretation: If rate increases after crushing a solid, which factor caused it?
Identify the best interpretation: If rate increases after crushing a solid, which factor caused it?
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Increased surface area of the solid. Crushing increases surface area for more reaction sites.
Increased surface area of the solid. Crushing increases surface area for more reaction sites.
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Identify the best interpretation: If rate increases after heating, which factor caused it?
Identify the best interpretation: If rate increases after heating, which factor caused it?
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Increased temperature. Heating increases particle energy and collision effectiveness.
Increased temperature. Heating increases particle energy and collision effectiveness.
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What is the overall effect of increasing surface area of a solid reactant on reaction rate?
What is the overall effect of increasing surface area of a solid reactant on reaction rate?
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Reaction rate increases. More exposed particles available for reaction at the surface.
Reaction rate increases. More exposed particles available for reaction at the surface.
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What is the overall effect of decreasing surface area of a solid reactant on reaction rate?
What is the overall effect of decreasing surface area of a solid reactant on reaction rate?
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Reaction rate decreases. Fewer exposed particles available for reaction at the surface.
Reaction rate decreases. Fewer exposed particles available for reaction at the surface.
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Which particle-level change best explains why greater solid surface area increases reaction rate?
Which particle-level change best explains why greater solid surface area increases reaction rate?
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More exposed particles lead to more collisions at the solid surface. Greater surface area provides more contact points for reactions.
More exposed particles lead to more collisions at the solid surface. Greater surface area provides more contact points for reactions.
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Identify the factor that mainly affects reactions involving a solid by exposing more particles: temperature, concentration, or surface area.
Identify the factor that mainly affects reactions involving a solid by exposing more particles: temperature, concentration, or surface area.
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Surface area. Surface area determines how much solid is available to react.
Surface area. Surface area determines how much solid is available to react.
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Which change affects rate for a reaction between a solid and a solution: increasing concentration or increasing solid surface area?
Which change affects rate for a reaction between a solid and a solution: increasing concentration or increasing solid surface area?
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Increasing solid surface area. Both factors are relevant for solid-solution reactions.
Increasing solid surface area. Both factors are relevant for solid-solution reactions.
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What is the expected rate change when temperature and concentration both increase, with all else constant?
What is the expected rate change when temperature and concentration both increase, with all else constant?
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Rate increases (both factors increase effective collisions). Both factors independently increase collision effectiveness.
Rate increases (both factors increase effective collisions). Both factors independently increase collision effectiveness.
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What is the expected rate change when concentration decreases but temperature increases, with all else constant?
What is the expected rate change when concentration decreases but temperature increases, with all else constant?
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Indeterminate without data; factors oppose each other. Competing effects make prediction impossible without magnitudes.
Indeterminate without data; factors oppose each other. Competing effects make prediction impossible without magnitudes.
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Which solid form reacts faster with acid: a single large chunk or the same mass as powder?
Which solid form reacts faster with acid: a single large chunk or the same mass as powder?
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Powder (greater surface area). Powdered form has much greater surface area than a chunk.
Powder (greater surface area). Powdered form has much greater surface area than a chunk.
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Which reacts faster: $25,^{\circ}\text{C}$ or $45,^{\circ}\text{C}$, assuming all else is constant?
Which reacts faster: $25,^{\circ}\text{C}$ or $45,^{\circ}\text{C}$, assuming all else is constant?
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$45,^{\circ}\text{C}$. Higher temperature increases particle energy and collision rate.
$45,^{\circ}\text{C}$. Higher temperature increases particle energy and collision rate.
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Which reacts faster: $0.10,\text{M}$ HCl or $1.0,\text{M}$ HCl, assuming all else is constant?
Which reacts faster: $0.10,\text{M}$ HCl or $1.0,\text{M}$ HCl, assuming all else is constant?
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$1.0,\text{M}$ HCl. Higher concentration provides more particles for collisions.
$1.0,\text{M}$ HCl. Higher concentration provides more particles for collisions.
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Which has the higher collision frequency in a fixed volume: $2.0,\text{M}$ or $0.50,\text{M}$ solution?
Which has the higher collision frequency in a fixed volume: $2.0,\text{M}$ or $0.50,\text{M}$ solution?
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$2.0,\text{M}$ solution. More particles per volume means more collisions per time.
$2.0,\text{M}$ solution. More particles per volume means more collisions per time.
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Which change affects rate for a reaction between two aqueous ions: increasing surface area or increasing concentration?
Which change affects rate for a reaction between two aqueous ions: increasing surface area or increasing concentration?
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Increasing concentration. Surface area doesn't apply to dissolved ions.
Increasing concentration. Surface area doesn't apply to dissolved ions.
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Which change would most likely decrease the initial rate: higher concentration or lower surface area of a solid?
Which change would most likely decrease the initial rate: higher concentration or lower surface area of a solid?
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Lower surface area of a solid. Lower surface area reduces available reaction sites.
Lower surface area of a solid. Lower surface area reduces available reaction sites.
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