Rate of Reactions

What is the meaning of the rate of reaction?

• Decrease in amount of product

• Decrease in amount of product against time

• Increase in amount of products against time

• Increase in amount of reactants against time

Tags

NGSS.HS-PS1-5

The following equation represents a chemical equation.

CaCO₃ + 2HCl --> CaCl₂ + CO₂ + H₂O

Which graph shows the correct change in mass of reactant used in excess against time?

• 
• 
• 
• 

Tags

NGSS.HS-PS1-7

The rate of reaction for the decomposition of hydrogen peroxide decreases with time because ...

• concentration of water decreases

• temperature of hydrogen peroxide decreases

• volume of hydrogen peroxide decreases

• concentration of hydrogen peroxide decreases

Tags

NGSS.HS-PS1-5

In which of the chemical reactions can the rate be determined by measuring the change in the gas volume?

• oxygen gas reacting with hydrogen gas

• Sodium hydroxide solution with dilute hydrochloric acid

• Silver nitrate solution with sodium chloride solution

• Calcium carbonate with dilute hydrochloride acid

Tags

NGSS.HS-PS1-5

The reaction between zinc, Zn and hydrochloric acid, HCl is represented by the following equation.

Zn + 2HCl --> ZnCl₂ + H₂

A student wants to determine the rate of reaction in a school laboratory. Which of the following methods is the most suitable?

• Determine the change in temperature of the solution by time

• Determine the change in the concentration of zinc chloride by time

• Determine the volume of hydrogen gas given off by time

• Determine the change in the concentration of hydrochloric acid by time

Tags

NGSS.HS-PS1-5

The following equation represents the reaction between calcium carbonate, CaCO₃ and hydrochloric acid, HCl.

CaCO₃ + 2HCl --> CaCl₂ + CO₂ + H₂O

Which changes can be used to determine the rate of reaction?

I : mass of calcium carbonate per unit time

II : Volume of carbon dioxide released per unit time

III : Colour of solution per unit time

IV : Mass of precipitate produced per unit time

• I and II

• I and III

• II and IV

• III and IV

Tags

NGSS.HS-PS1-5

Diagram shows a graph of volume of oxygen gas collected against time in the decomposition reaction of hydrogen peroxide when using manganese dioxide as catalyst.

Which point shows the highest rate of reaction?

• P

• Q

• R

• S

Tags

NGSS.HS-PS1-5

Which of the followings does not affect the rate of a chemical reaction?

• temperature

• concentration

• particle size (surface area)

• none of them

Tags

NGSS.HS-PS1-5

The rate of a reaction increases as temperature__________________.

• Decreases

• Increases

• Stays the same

• Variable

Tags

NGSS.HS-PS1-5

Products will form faster if____________

• the particle size of the reactants are larger.

• temperature is decreased.

• concentration of the reactants are increased.

• the reaction is not stirred.

Tags

NGSS.HS-PS1-5