Chem 1.1

When investigating the effect of concentration on a reaction what must we keen the same?

• Temperature & concentration

• Concentration and surface area

• surface area & mass and temperature

To change the concentration of acid we reduced the volume of acid and increased the volume of water, why did we always have 10mL of acid solution?

• for a fair test

• So we accurately knew the concentration of the acid

• because volume of acid was a controlled variable

• Because the reactant particles would be closer to the metal in a smaller volume

• all of the above

To change the surface area of a reactant we could...

• use large pieces and powder

• dilute with water

• change the temperature of acid

When changing the surface area why must the mass of reactants be the same for all trials?

• To change surface area

• So all trials have the same number of reactant particles present.

• To have the same mass

• for a fair test

When investigating the effect of temperature on a reaction. Temperature is the ...

• controlled variable

• dependent variable

• independent variable

When investigating the effect of temperature on a reaction. the speed/ rate of reaction is the ...

• controlled variable

• dependent variable

• independent variable

When we increase the concentration of acid the speed/rate of reaction increases because....

• particles have more kinetic energy and collide more frequently

• There are more particles present in the solution so they collide more frequently

• there are more particles available to collide with the acid leading to more frequent collisions

I increase the accuracy of my results by ....

• reading volumes accurately, by measuring at eye level (parallax error) and to the bottom of the meniscus.

• accounting for zero error when necessary

• using the same person on the stopwatch, same reaction time

• All of the above

What is the purpose of a catalyst?

• Helps to slow down a reaction

• Raises the activation energy

• Lowers the activation energy

• Is consumed by the reaction

With the increase in temperature, the average kinetic energy of the molecules increases, leading to a decrease in number of collisions per unit time.

• True
• False

Tags

NGSS.HS-PS1-5