Balancing Chemical Equations and Conservation of Mass

What common factor is essential for airbags, campfires, acid rain, and the synthesis of medicines?

• Biological processes

• Mechanical processes

• Chemical reactions

• Physical changes

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following is NOT a visible sign of a chemical change?

• Color change

• Formation of a precipitate

• Change in volume

• Production of gas

Tags

NGSS.MS-PS1-2

What is the purpose of using the 'tare' function on an electronic balance?

• To add the mass of the container

• To measure the volume of a liquid

• To zero out the mass of the container

• To measure the density of a substance

What observation indicates that energy is being absorbed during a chemical reaction?

• The mixture gets warmer

• The mixture changes color

• The mixture gets cooler

• The mixture produces light

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

NGSS.MS-PS3-5

What does the law of conservation of mass state?

• Mass can only decrease during a reaction

• Mass can be created or destroyed

• Mass remains constant before and after a reaction

• Mass can only increase during a reaction

Tags

NGSS.MS-PS1-5

In a balanced chemical equation, what does the arrow represent?

• A subtraction sign

• A plus sign

• An equal sign

• A multiplication sign

What do the letters 's', 'g', 'l', and 'aq' represent in a chemical equation?

• Silicon, graphite, lead, aquifer

• Sulfur, glucose, lead, aquamarine

• Solid, gas, liquid, aqueous

• Sodium, gold, lithium, aqua

What is the significance of coefficients in a chemical equation?

• They indicate the temperature of the reaction

• They show the state of the substance

• They represent the quantity needed for a reaction

• They indicate the number of atoms in a molecule

Tags

NGSS.HS-PS1-7

Why are hydrogen and oxygen represented as diatomic molecules in chemical equations?

• They are only found in solid form

• They are more stable as single atoms

• They do not react with other elements

• They are always found in pairs in nature

What is the correct balanced equation for the formation of water from hydrogen and oxygen?

• 2H2 + O2 -> 2H2O

• H2 + O2 -> H2O

• 2H + O2 -> H2O

• H + O -> H2O

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-5