Chemical Reactions and Balancing Equations

Pick the true statements.

• In chemical reactions, the atoms rearrange

• Some atoms disappear in chemical reactions

• Atoms can change their mass in chemical reactions

• There are the same numbers of atoms in the products as there are in the reactants

• Atoms are joined together differently in the reactants than they are in the products

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Word Equation:

Sodium + Chlorine > Sodium chloride

Complete the balanced symbol equation:

2___ + Cl₂ > __ NaCl

Tags

NGSS.MS-PS1-5

Finish the word equation:

Iron + ______ > Iron oxide

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Two solutions react in a beaker. The outside of the beaker begins to feel warm. Is this an endothermic or exothermic reaction?

• endothermic

• exothermic

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-5

What is the right ratio of chemicals for the balanced chemical equation?

__CO + __Fe₂O₃--> __Fe + __CO₂

• 3,1 --> 2,3

• 3,2 --> 1,1

• 3,2 --> 2,4

• 3,2 --> 2,1

Tags

NGSS.MS-PS1-5

Some students decomposed potassium chlorate powder into potassium chloride and oxygen gas. Which equation for this reaction is correctly balanced?

Tags

NGSS.MS-PS1-5

Balance this reaction: ____ AlBr₃ + ____ K₂SO₄ ---> ____ KBr + ____ Al₂(SO₄)₃

• 1,1,1,1

• 2,3,6,1

• 2,6,1,1

• 3,1,2,2

Tags

NGSS.MS-PS1-5

How many HCl molecules do you need to balance this equation?

2Mg + ​ (a)   HCl ---> 2MgCl₅ + 5H₂

• 10

• 1

• 2

• 5

Tags

NGSS.MS-PS1-5

Which set of coefficients will correctly balance the following chemical reactions?

• 1,2,1,2

• 2,1,2,1

• 1,2,1,1

• 2,1,1,1

Tags

NGSS.MS-PS1-5

• 6

• 12

• 18

• 24

Answer explanation

To balance the reaction, we need 6 molecules of CO2 on the product side, so the correct coefficient for CO2 is 6.

Tags

NGSS.MS-PS1-5