chemical reactions

Which of the following models best demonstrates a balanced chemical equation?

• F

• G

• H

• J

Tags

NGSS.HS-PS1-7

Why must chemical equations be balanced?

• So that the equation doesn't explode

• The reaction won't happen until it is balanced

• Based on the Law of Conservation of Matter, matter cannot be created or destroyed.

• Based on the Law of Conservation of Energy, energy cannot be created or destroyed.

Tags

NGSS.HS-PS1-7

Balance this equation...

HgO --> Hg + O₂

• It is balanced

• 2HgO --> Hg + O₂

• 2HgO --> 2Hg + O₂

Tags

NGSS.HS-PS1-7

Balance this equation...

H₂ + Cl₂ --> HCl

• It is balanced

• 3H₂ + Cl_{2 -->} 6H₂Cl

• H₂ + Cl_{2 -->} 2HCl

• H₂ + Cl₂ --> H₂Cl₂

Tags

NGSS.HS-PS1-7

Which are the reactants in the following reaction?

2Mg + O₂ ---> 2MgO

• Mg and O₂

• MgO

• Mg and MgO

• O₂ and MgO

Tags

NGSS.MS-PS1-2

How many Nitrogen (N) atoms are in 4NH₃?

• 4

• 1

• 3

• 12

Tags

NGSS.MS-PS1-1

Is this equation balanced?

• Yes

• No

Tags

NGSS.HS-PS1-7

To balance an equation you should:

• ONLY change subscripts.

• ONLY change coefficients.

• Change BOTH subscripts and coefficients.

Tags

NGSS.MS-PS1-5

solid sodium reacts with chlorine gas to produce solid sodium chloride. The correct UNBALANCED equation is:

• NaCl_(s)→ Cl _(g) + Na _(s)

• Na _(s)+ CO_{2 (g)} → NaCO_{2 (s)}

• Na _(s) + Cl_{2 (g)}→ NaCl _(s)

• Na _(s) + Cl _(g) → NaCl _(s)

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

When hydrogen gas reacts with solid sulfur, a smelly gas, dihydrogen monosulfide, is produced. The correct UNBALANCED equation for this reaction is:

• H_2(g) + S _(g) → HS _(g)

• H_{2 (g)}+ S _(s)→ H₂S _(g)

• H _(g)+ S _(s) → HS _(g)

• H_{2 (g)} + S _(g) → H₂S _(g)

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2