Chemical Change

The next day, the class continued their investigation by mixing sodium bicarbonate (NaHCO₃) with acetic acid (C₂H₄O₂), commonly known as vinegar. Their new data table is shown below:

 

The Results of Mixing Sodium Bicarbonate with Two Different Solutions

Look at the data from the investigation with acetic acid. Which group’s data is an outlier?

• Group 1

• Group 2

• Group3

• Group 5

• Group 7

Tags

NGSS.MS-PS1-2

A scientist heats 10 mL of water in a test tube over a Bunsen burner for two minutes. The water reaches boiling point and turns into steam, with bubbles forming. This process is a chemical reaction due to the formation of bubbles.

• True

• False

Tags

NGSS.MS-PS1-4

Which of the following processes does NOT involve a chemical change?

• • food being broken down in the stomach

• • mixing vinegar and baking soda

• • combining hydrochloric acid and sodium hydroxide

• • snow melting

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

A class of students were investigating the properties of sodium bicarbonate (NaHCO3), commonly known as baking soda. Each lab group mixed sodium bicarbonate with calcium chloride (CaCl2) in a beaker. They measured the temperature of the solution immediately after mixing the chemicals and continued taking observations until the temperature stopped changing. They recorded their observations in the data table below.

What is the average change in temperature for this experiment?

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

NGSS.MS-PS3-4

Mrs. Holmes asked her TA, Watson, to label jars of 4 chemicals with the chemical formulas of the substances: NaCl, NaHCO₃, C₁₂H₂₂O₁₁, and CaCO₃. Unfortunately, Watson was interrupted in the middle of the task by a fire drill. Mrs. Holmes now has 4 unlabeled jars of chemicals. Some properties of the chemicals are given in the table below.

Selected Properties of Four Chemicals

Mrs. Holmes thinks the substance in jar 3 is either C₁₂H₂₂O₁₁ or NaCl. How could she find out which it is?

• She could calculate the density of the substance.

  
  

• She could put the substance in vinegar.

  
  

• She could put the substance in water.

  
  

• She could try to set a sample of the substance on fire.

Tags

NGSS.MS-PS1-2

The next day, the class continued their investigation by mixing sodium bicarbonate (NaHCO₃) with acetic acid (C₂H₄O₂), commonly known as vinegar. Their new data table is shown below:

 

The Results of Mixing Sodium Bicarbonate with Two Different Solutions

Which of the following statements is best supported by the evidence in the data table?

• There is not enough evidence to tell whether sodium bicarbonate reacts with either substance.

  
  

• Sodium bicarbonate reacts with both acetic acid and calcium chloride.

  
  

• Sodium bicarbonate reacts with calcium chloride but not with acetic acid.

  
  

• Sodium bicarbonate reacts with neither acetic acid or calcium chloride.

  
  

• Sodium bicarbonate reacts with acetic acid but not with calcium chloride.

Tags

NGSS.MS-PS1-2

Which of the following does NOT indicate that a chemical reaction has occurred?

• • The substances involved in the reaction undergo a color change.

• • Mixing two chemicals results in a significant temperature shift.

• • The materials formed after the reaction have a different size or shape.

• • A strong smell is released when two chemicals react.

Tags

NGSS.MS-PS1-2

The next day, the class continued their investigation by mixing sodium bicarbonate (NaHCO₃) with acetic acid (C₂H₄O₂), commonly known as vinegar. Their new data table is shown below: The Results of Mixing Sodium Bicarbonate with Two Different Solutions

Which of the following is the most logical explanation for the outlier?

• The group used half as much acetic acid as the other groups.

  
  

• The group took their measurements in Fahrenheit instead of Celsius.

  
  

• The group used twice as much acetic acid as the other groups.

  
  

• The group used twice as much acetic acid as the other groups.

Tags

NGSS.MS-PS1-2

On a molecular level, what is the pattern found in every chemical reaction?

• Molecules are destroyed and disappear.

• New atoms are created during the reaction.

• Atoms are rearranged to form new substances.

• The number of molecules increases without any change in structure.

Tags

NGSS.MS-PS1-5

Which of the following is an example of a chemical reaction?

• a solid forming in solution

  
  

• ice melting

  
  

• water boiling

  
  

• a tire losing air

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5