Chemical Equations Test Review

Which of the following states the law of conservation of mass?

• Mass cannot be created or destroyed in a chemical reaction

• Mass cannot be created or destroyed in a chemical reaction

• Energy is neither created nor destroyed in a chemical reaction

• Atoms are rearranged in a chemical reaction, and some join new molecules

Tags

NGSS.MS-PS1-5

T or F: Leaves changing colors in the fall are an example of chemical change/reaction

• True

• False

Tags

NGSS.MS-PS1-2

How many hydrogen atoms are in this glucose molecule?

C₆H₁₂O₆

• 3

• 6

• 12

• None

Tags

NGSS.MS-PS1-1

How many sodium atoms are present in this molecule? 7Na₃PO₄

• 7

• 3

• 4

• 21

Tags

NGSS.MS-PS1-1

Which is the product in this chemical formula?

Ca + Cl₂ --> CaCl₂

• Ca

• Cl₂

• CaCl₂

What are the reactants in this chemical equation?

Ca + Cl₂ --> CaCl₂

• Ca

• Cl₂

• CaCl₂

• Ca & Cl₂

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-2

In which kind of chemical reaction do two or more substances combine to form one new compound?

• synthesis reaction

• single-displacement reaction

• double-displacement reaction

• decomposition reaction

Tags

NGSS.MS-PS1-1

What coefficient should be placed in front of the HCl so that the reaction obeys the Law of Conservation of Mass?

Ca+__HCl → CaCl2+H2

• 1

• 2

• 3

• 4

Tags

NGSS.MS-PS1-5

T or F: An equation can have different numbers of atoms on each side

• True

• False (it shouldn't have different

Tags

NGSS.MS-PS1-5

Which of the following is the best explanation as to why chemical equations need to be balanced?

• Because an equation cannot have different numbers of atoms on each side

• Because an equation cannot have more products than reactants

• Because an equation cannot have more reactants than products

• Because an equation cannot have the same number of atoms on both sides

Tags

NGSS.MS-PS1-5