Unit 5 Chemical Reactions Review

Chemical reaction = _______

• Process by which substances collide with enough energy that new bonds are formed between atoms, thus creating new substances

• Process by which substances are mixed without any chemical change

• Process by which substances are heated without any reaction

• Process by which substances are dissolved in water

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Reactants = _______

• Starting substances

• Ending substances

• Catalysts

• Products

Products = _______

• Ending substances

• Starting materials

• Intermediate compounds

• Catalysts

Aqueous = _______

• Dissolved in water

• Solid in water

• Evaporated in air

• Condensed in liquid

Tags

NGSS.HS-ESS2-5

Which of the following best differentiates between physical and chemical changes?

• Physical changes alter the form of a substance, while chemical changes alter the substance itself.

• Physical changes result in new substances, while chemical changes do not.

• Physical changes are always reversible, while chemical changes are not.

• Physical changes involve energy changes, while chemical changes do not.

The collision theory is significant in chemical reactions because ...

• It describes the energy changes during a reaction.

• It explains how and why reactions occur.

• It provides the exact speed of a reaction.

• It determines the color change in reactions.

Tags

NGSS.HS-PS1-5

Which of the following are signs that can provide evidence that a chemical reaction has occurred?

• Change in color, formation of a precipitate, and emission of gas

• Increase in temperature, decrease in volume, and change in shape

• Absorption of light, increase in mass, and change in texture

• Decrease in pressure, increase in density, and change in size

Tags

NGSS.MS-PS1-2

Explain the Law of Conservation of Mass in relation to chemical reactions.

• Matter can be created or destroyed in a system.

• Matter can only change forms, not be created or destroyed.

• The mass of the reactants is always less than the mass of the products.

• The mass of the products is always less than the mass of the reactants.

Tags

NGSS.HS-PS1-7

Differentiate between coefficients and subscripts in a chemical reaction.

• Coefficients indicate the number of molecules, while subscripts indicate the number of atoms in a molecule.

• Coefficients indicate the number of atoms in a molecule, while subscripts indicate the number of molecules.

• Coefficients and subscripts both indicate the number of molecules.

• Coefficients and subscripts both indicate the number of atoms in a molecule.

List the number of atoms of each element in the compound Mg₃(PO₄)₂.

• Mg: 3, P: 2, O: 8

• Mg: 1, P: 1, O: 4

• Mg: 3, P: 1, O: 4

• Mg: 1, P: 2, O: 8

Tags

NGSS.MS-PS1-1