Chemical Reactions review

Reactants and products in chemical reactions may be

• elements.

• compounds.

• exactly the same compounds.

• none of the above.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

All chemical changes in matter involve

• changes of state.

• chemical reactions.

• changes in color.

• two of the above.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following changes is a chemical change?

• ice melting

• wax melting

• water boiling

• wax burning

Tags

NGSS.MS-PS1-2

Which statement is true of all chemical reactions?

• They can go in just one direction.

• They occur only in science labs.

• They break and reform bonds.

• They create new elements.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which statement is true about a precipitate?

• It is a solid.

• It settles out of a liquid solution.

• It is evidence of a chemical reaction.

• all of the above

Tags

NGSS.MS-PS1-2

Which chemical equation correctly represents the reaction in which carbon combines with oxygen?

• C₂ + O₂ → 2CO

• C₂ + 2O → C₂O₂

• C + O₂ → CO₂

• 2C + O → C₂O

Tags

NGSS.MS-PS1-5

If there is more than one product in a chemical equation, the products are separated by

• plus signs.

• minus signs.

• equal signs.

• two-way arrows.

Which chemical equation is not balanced?

• 2Na + Cl₂ → 2NaCl

• C + O₂ → CO₂

• NO + O₂ → 2NO₂

• N₂ + 3H₂ → 2NH₃

Tags

NGSS.MS-PS1-5

In chemical equations, reactants and products are represented by

• plus signs and arrows.

• elements and compounds.

• coefficients and subscripts.

• chemical symbols and chemical formulas.

What is the missing coefficient in the following chemical equation? CH₄ + ?O₂ → CO₂ + 2H₂O

• 3

• 2

• 1

• 0

Tags

NGSS.MS-PS1-5