Law of Conservation of Mass

Multiple Choice

In a chemical reaction, the mass of the products must equal the mass of the what?

• Reactants

• Catalysts

• Solvents

• Inhibitors

Multiple Choice

Which of the following is NOT a learning goal mentioned in the document?

• Identify reactants and products

• Explain the law of conservation of mass

• Understand the periodic table

• Model how atoms are conserved

Multiple Choice

Which of the following is a goal related to understanding chemical reactions?

• Model how atoms are conserved

• Measure temperature changes

• Calculate reaction rates

• Identify chemical bonds

Multiple Choice

How can chemical reactions occur?

• Only quickly

• Only slowly

• Quickly or slowly

• Neither quickly nor slowly

Multiple Choice

What type of chemical reaction is a fireworks explosion?

• Slow

• Fast

• Gradual

• Non-reactive

Multiple Choice

What is the product in the given chemical reaction?

• 2Mg(s)

• O₂(g)

• 2MgO(s)

• Reaction Arrow

Multiple Choice

What is the role of reactants in a chemical reaction?

• They are produced

• They are consumed

• They remain unchanged

• They act as catalysts

Multiple Choice

How are atoms arranged in products compared to reactants?

• Identically

• Differently

• Randomly

• Not at all

Multiple Choice

In the product of the given example, how many atoms of magnesium are present?

• 1

• 2

• 3

• 4

Multiple Choice

What does the reaction arrow indicate in a chemical equation?

• The start of the reaction

• The end of the reaction

• The direction of the reaction

• The temperature of the reaction

Multiple Choice

How many atoms do you have in the compound 2MgCl₂?

• 2 atoms

• 4 atoms

• 6 atoms

• 8 atoms

Multiple Choice

How many Ca (Calcium) atoms are found in Ca(OH)_2?

• 5 atoms

• 3 atoms

• 2 atoms

• 1 atom

Multiple Choice

How many atoms do you have in the chemical formula 3H₂O₂?

• 7 atoms

• 12 atoms

• 4 atoms

• 6 atoms

Multiple Choice

How many atoms do you have in the chemical formula 2Mg(ClO₃)₂?

• 2 atoms

• 7 atoms

• 9 atoms

• 18 atoms

Multiple Choice

Law of conservation of mass states the amounts of atoms in the reactants and the products...

• Increase

• Decrease

• Stay the same

• No correct answer

Multiple Choice

Does the equation H₂+O₂ →H₂O follow the Law of Conservation of Mass?

• Yes, because the atoms are equal.

• No, because more info is needed.

• No, because there are more atoms in the product.

• No, because there are more atoms in the reactant.

Multiple Choice

The Law of Conservation of Mass means that...

• The Mass of the reactants & products are equal.

• The Atoms of the reactants & products are equal.

• No mass or atoms is gained or lost during a chemical reaction.

• All the states are correct.

Multiple Choice

In this reaction, how much CO₂ is produced?

• 42 g

• 24 g

• 23 g

• No grams produced

Multiple Choice

In this reaction, how much O₂ is produced?

• 12 g

• 22 g

• 42 g

• No grams are produced

Multiple Choice

In a reaction A + B → C, reactant A has 5 g and product C has 9 g. How many grams does reactant B should have?

• 4 g

• 5 g

• 9 g

• 14 g

Multiple Choice

Does this equation follow the Law of Conservation of Mass?

2Fe₂O₃ + 3C → 4Fe + 3 CO₂

• No, because there are more reactants than products.

• No, because there are more products than reactants.

• Yes, because the reactants equal the products.

• Yes, because the reactants do not equal the products.

Multiple Choice

If a reaction starts with a total 75 g of reactants it should produce

• a total of 40 g of products

• a total of 75 g of products

• a total of 180 g of products

• No correct answer

Multiple Choice

If there are 4 Hydrogen atoms on the reactant side, how many Hydrogen atoms will be on the product side?

• More information is needed to answer

• 6 atoms

• 4 atoms

• 2 atoms

Multiple Choice

What is the part of the chemical equation in green called?

Fe + S → FeS

• Reactants

• Products

• Yield

• Chemical equation

Multiple Choice

What is the right part of a chemical equation called...

2H_{2 +} O₂ → 2H₂O

• Reactants

• Products

• Yield

• Chemical Equation