Which statement is true about the total mass of the reactants during a chemical change? 4.01

• It is destroyed during chemical reaction.

• It is less than the total mass of the products.

• It is equal to the total mass of the products.

• It is greater than the total mass of the products.

Tags

NGSS.HS-PS1-7

Based on the law of conservation of mass, which of the following statements is correct? 4.01

• Matter is neither created nor destroyed.

• Matter can be created but it cannot be destroyed.

• The total mass of substances before a reaction is less than the total mass after a reaction.

• The total mass of substances before a reaction is greater than the total mass after a reaction.

Tags

NGSS.HS-PS1-7

Which of the following happens during a chemical reaction? 4.01

• Atoms of reactants are destroyed.

• New atoms are created to form the products.

• Atoms of reactants rearrange to form new substances.

• The total mass of the reactants is less than the total mass of the products.

Tags

NGSS.HS-PS1-7

Look at the chemical equation:

Zn + 2HCl → ZnCl₂ + H₂

How many atoms of hydrogen (H) are present on both sides of the equation? 4.01

• 1

• 2

• 3

• 4

Tags

NGSS.HS-PS1-7

Look at the chemical equation:

3H₂ + N₂ → 2NH₃

How many atoms of hydrogen (H) are present on both sides of the equation? 4.01

• 2

• 3

• 5

• 6

Tags

NGSS.HS-PS1-7

Look at the chemical equation:

2H₂S + 3O₂ → 2H₂O + 2SO₂

How many atoms of hydrogen (H) are present on both sides of the equation? 4.01

• 2

• 3

• 4

• 6

Tags

NGSS.MS-PS1-5

Which of the following equations is balanced? 4.01

• 2H₂ + O₂ → 4H₂O

• 4Na + O₂ → 2Na₂O

• Fe₂O₃ + H₂ → 2Fe + 3H₂O

• CH₄ + O₂ → CO₂ + H₂O

Tags

NGSS.HS-PS1-7

Which of the following equations is balanced? 4.01

• 2H₂ + O₂ → 2H₂O

• 2Na + O₂ → 2Na₂O

• FeS + HCl → 2FeCl₂ + H₂S

• NH₄OH → NH₃ + 2H₂O

Which of the following equations is balanced? 4.01

• 2Al + 3O₂ → Al₂O₃

• N₂ + 2H₂ → 2NH₃

• CH₄ + 3O₂ → CO₂ + 2H₂O

• 2Fe2O₃ + 3C → 4Fe + 3CO₂

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A chemical equation is shown below.

KNO₃ → KNO₂ + O₂

What are the coefficients that should be added to balance this equation? Use complete sentences to explain your answer.

Explain how this chemical reaction demonstrates the conservation of mass. 4.01

Tags

NGSS.HS-PS1-7