Balancing Equations

The numbers placed in ​ (a)   of formulas to balance equations are called ​ (b)   , and they multiply all the atoms in a ​ (c)   . Thus, the symbol “2NaHCO₃” indicates ​ (d)   units of sodium bicarbonate, which contain 2 Na atoms, 2 H atoms, 2 C atoms, and 6 O atoms

(2 X 3= 6, the coefficient times the subscript for O).

• front

• coefficients

• two

• formula

What is the balanced equation for the combustion of methane (CH4)?

• @@ ext{CH}_4 + 2 ext{O}_2 ightarrow ext{CO}_2 + 2 ext{H}_2 ext{O}@@

• @@ ext{CH}_4 + ext{O}_2 ightarrow ext{CO}_2 + ext{H}_2 ext{O}@@

• @@2 ext{CH}_4 + 3 ext{O}_2 ightarrow 2 ext{CO}_2 + 4 ext{H}_2 ext{O}@@

• @@ ext{CH}_4 + 3 ext{O}_2 ightarrow ext{CO}_2 + 2 ext{H}_2 ext{O}@@

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following represents a balanced chemical equation?

• @@ ext{H}_2 + ext{O}_2 ightarrow ext{H}_2 ext{O}@@

• @@2 ext{H}_2 + ext{O}_2 ightarrow 2 ext{H}_2 ext{O}@@

• @@ ext{H}_2 + 2 ext{O}_2 ightarrow 2 ext{H}_2 ext{O}@@

• @@2 ext{H}_2 + 2 ext{O}_2 ightarrow 2 ext{H}_2 ext{O}@@

Tags

NGSS.MS-PS1-5

In a balanced chemical equation, the number of atoms of each element on the reactant side must be equal to the number on the product side. Which law does this illustrate?

• Law of Conservation of Mass

• Law of Definite Proportions

• Law of Multiple Proportions

• Law of Conservation of Energy

Tags

NGSS.MS-PS1-5

What is the coefficient of oxygen when balancing the equation: @@ ext{C}_3 ext{H}_8 + ext{O}_2 ightarrow ext{CO}_2 + ext{H}_2 ext{O}@@?

• 5

• 3

• 4

• 2

Tags

NGSS.MS-PS1-5

Which of the following is the balanced equation for the reaction of hydrogen gas with nitrogen gas to form ammonia?

• @@ ext{H}_2 + ext{N}_2 ightarrow ext{NH}_3@@

• @@3 ext{H}_2 + ext{N}_2 ightarrow 2 ext{NH}_3@@

• @@2 ext{H}_2 + ext{N}_2 ightarrow 2 ext{NH}_3@@

• @@ ext{H}_2 + 3 ext{N}_2 ightarrow 2 ext{NH}_3@@

Tags

NGSS.MS-PS1-5

When balancing the equation @@ ext{Fe} + ext{O}_2 ightarrow ext{Fe}_2 ext{O}_3@@, what is the coefficient for iron (Fe)?

• 4

• 2

• 3

• 1

Tags

NGSS.MS-PS1-5

Which of the following is a balanced equation for the decomposition of water?

• @@2 ext{H}_2 ext{O} ightarrow 2 ext{H}_2 + ext{O}_2@@

• @@ ext{H}_2 ext{O} ightarrow ext{H}_2 + ext{O}_2@@

• @@2 ext{H}_2 ext{O} ightarrow ext{H}_2 + 2 ext{O}_2@@

• @@ ext{H}_2 ext{O} ightarrow 2 ext{H}_2 + ext{O}_2@@

Tags

NGSS.MS-PS1-5

In the reaction @@ ext{Al} + ext{O}_2 ightarrow ext{Al}_2 ext{O}_3@@, what is the coefficient for aluminum (Al) when balanced?

• 4

• 2

• 3

• 1

Tags

NGSS.MS-PS1-5

What is the balanced equation for the reaction of sodium with chlorine gas to form sodium chloride?

• @@2 ext{Na} + ext{Cl}_2 ightarrow 2 ext{NaCl}@@

• @@ ext{Na} + ext{Cl}_2 ightarrow ext{NaCl}@@

• @@2 ext{Na} + 2 ext{Cl}_2 ightarrow 2 ext{NaCl}@@

• @@ ext{Na} + 2 ext{Cl}_2 ightarrow ext{NaCl}@@

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5