Chemical Reactions

Chemical reactions ___________.

• occur only in living organisms

• create and destroy atoms

• only occur outside living organisms

• produce new substances

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following is not a true statement concerning what happens in all chemical reactions?

• The ways in which atoms are joined together are changed.

• New atoms are formed as products.

• The starting materials are named reactants.

• In a word equation representing a chemical reaction, the reactants are written on the left and the products on the right.

Tags

NGSS.HS-PS1-7

What does the symbol Δ mean when included in a chemical equation?

• heat is supplied to the reaction

• a catalyst is needed

• yields

• precipitate

Chemical equations __________.

• describe chemical reactions

• show how to write chemical formulas

• give directions for naming chemical compounds

• describe only biological changes

Tags

NGSS.HS-PS1-7

A skeleton equation does not show which of the following?

• the reactants on the left, the products on the right

• an arrow connecting the reactants to the products

• the physical states of the substances

• the relative amounts of reactants and products

Chemical equations may describe ________.

• electrochemical processes

• chemical reactions

• biological reactions

• All the above

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-4

Chemical equations must be balanced to satisfy the ________.

• law of definite proportions

• law of multiple proportions

• law of conservation of mass

• principle of Avogadro

Tags

NGSS.HS-PS1-7

Which set is used in chemical equations?

• (g), grams

• (aq), dissolved in water

• (sp), solid product

• (lq), gas

Tags

NGSS.MS-PS1-5

In the chemical equation, H₂O₂(aq) → H₂O(l) + O₂(g), the H₂O₂ is a .

• product

• reactant
• solid

• gas

Tags

NGSS.MS-PS1-5

The symbol with 2 arrows, as shown to the right, indicates .

• that heat must be applied

• an incomplete combustion reaction

• that a gas is formed by the reaction

• that the reaction is reversible