Law of conservation of mass

What does the Law of Conservation of Mass say? It says,

"During a chemical reaction, mass is neither _______ or destroyed."

• burned

• created

• melted

Tags

NGSS.MS-PS1-5

The substances that go into a reaction are called the _______.

• products

• reactants

Tags

NGSS.MS-PS1-1

So, the Law of Conservation of Mass would tell us that the mass of all the REACTANTS must __________ the mass of all PRODUCTS in a chemical reaction.

• equal

• be greater than

• be less than

Tags

NGSS.MS-PS1-5

True or False: A reactant is a substance present at the beginning of a chemical reaction.

• True

• False

In a chemical reaction what is the product?

• a substance that is present at the beginning of a chemical reaction

• a substance that is produced during a chemical reaction

• a number written before a chemical formula to show how many atoms or molecules of that substance are involved in a chemical reaction

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-1

Examine the following chemical equation, which shows only the reactants and one product.

Zn + 2HCl ➡️ ZnCl₂ + ?

How many H atoms must be present in the second product that is formed?

• 1

• 2

• 3

• 4

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-1

NGSS.MS-PS1-2

Which of the following equations does not demonstrate the law of conservation of mass?

• 2Na + Cl₂ ➡️ 2NaCl

• NaOH + HCl ➡️ NaCl + H₂0

• P₄ + 5O₂ ➡️ 2P₄O₁₀

Tags

NGSS.MS-PS1-5

The substances listed on the right side of a chemical equation are the

• Yields
• Reactants
• Products
• Precipitates

Identify the reactant(s) and product(s) of the reaction.

• All three are reactants and none are products.
• Hydrogen and water are the reactants, and oxygen is the product.
• Water and oxygen are the reactants, and hydrogen is the product.
• Hydrogen and oxygen are the reactants, and water is the product.
  

How many Oxygen (O) atoms are in 2C₂HO₈C_l2

• 2
• 16
• 8
• 5

Tags

NGSS.MS-PS1-1