Chemical Reactions Concept Evaluation

The table shows the chemical formulas for four substances.

Which substances have the same number of carbon atoms?

• Substances 1 & 2

• Substances 2, 3, & 4

• Substances 2 & 3

• Substances 1 & 3

Tags

NGSS.MS-PS1-1

Which of these formulas contain equal numbers of nitrogen atoms?

• Formulas I and II

• Formulas I and IV

• Formulas II and III

• Formulas I, II and V

Tags

NGSS.MS-PS1-1

The equation represents a chemical reaction that occurs in living cells. How many atoms are represented in the reactants of this equation?

• 6

• 12

• 24

• 36

Tags

NGSS.MS-PS1-5

NGSS.MS-LS1-6

A student obtains two strips of magnesium (Mg) ribbon that are each 3cm long. One strip of magnesium is placed in a test tube containing 5 ml of water, and the other strip is placed in a test tube containing 5ml of hydrochloric acid (HCl). Both liquids are at room temperature. The student's observations are recorded in the table.

Which statement is NOT supported by the student's observations?

• A chemical reaction takes place between magnesium and hydrochloric acid.

• A gas is released in Test Tube 2.

• The substances in both test tubes are reactive only at high temperatures.

• Energy is released in the reaction involving hydrochloric acid.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

NGSS.MS-PS3-5

For an investigation a student poured a blue solution of CuSO₄ into a beaker. The student placed a shiny, silver-colored strip of zinc metal in the solution and observed the changes.

The student inferred that a chemical reaction occurred. What evidence supports this inference?

• A dark solid formed on the zinc metal.

• The zinc metal remained silver-colored and shiny.

• The CuSO₄ solution turned blue when the zinc metal was added.

• None on these

Tags

NGSS.MS-PS1-2

A scientists performed 4 investigations using 8 different liquids. In each investigation, the scientist combined 2 of the liquids under a fume hood and recorded observations in the table below.

In which investigation is it least likely that the liquids reacted chemically?

• Investigation 1

• Investigation 2

• Investigation 3

• Investigation 4

Tags

NGSS.MS-PS1-2

A chemical reaction in which Calcium Carbonate, CaCO₃, is decomposed results in the production of simpler compounds.

What mass of Calcium Carbonate, to the nearest hundredth of a gram, is decomposed in this reaction?

• 7.13

• 49.97

• 58.13

• There is no way to determine this.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A student listed how different parts of the body work to aid in the digestion of food.

Which of the following is a chemical change that occurs to the food?

• The reduction in the size of food particles as food is chewed

• The movement of food to the stomach as the food is swallowed

• The breakdown of molecules of food by enzymes and acid in the stomach

• None of the above

Some students are using samples of different substances for a lab investigation. They plan to observe the physical properties of each substance and record their observations in a table like the one below.

Which of the substances observed are elements?

• S, Fe, O₂, Sr and Al

• S, O₂ and LiF

• N₂O₄, O₂, and LiF

• N₂, O₄, Fe, Sr and Al

Tags

NGSS.MS-PS1-1

In the chemical reaction shown, the products are best classified as---

• Two elements

• One element and one compound

• Two compounds

• Two compounds and one element

Tags

NGSS.MS-PS1-2