8th Grade Presentation Conservation of Matter/Chem Reactions

Multiple Choice

What is the significance of the law of conservation of mass in chemical reactions?

• It explains why mass is lost during reactions.

• It shows that mass is created in chemical reactions.

• It states that mass is neither created nor destroyed in a chemical reaction.

• It only applies to physical changes.

Open Ended

What information is given in a chemical equation?

Multiple Choice

What is the main purpose of a chemical equation?

• To describe what happens in a chemical reaction using numbers and symbols

• To list all the elements in the periodic table

• To show the physical properties of substances

• To explain the history of chemistry

Open Ended

Explain the difference between reactants and products in a chemical equation.

Multiple Select

Which of the following are parts of a chemical equation as shown in the images?

• Coefficient

• Subscript

• Chemical formula

• Periodic table

Multiple Choice

In the chemical equation 2H₂O → 2H₂ + O₂, what does the number '2' in front of H₂O represent?

• Coefficient

• Subscript

• Product

• Reactant

Multiple Choice

What does the Law of Conservation of Mass state in relation to a chemical equation?

• The mass of reactants equals the mass of products

• The mass of products is always greater than reactants

• Mass is lost during a chemical reaction

• Only gases are conserved in a reaction

Multiple Choice

Which statement best describes the Law of Conservation of Mass as shown in the reaction between iron and oxygen to form rust?

• The total mass of reactants equals the total mass of products.

• Mass is lost during the reaction.

• New mass is created in the reaction.

• Only iron is conserved in the reaction.

Open Ended

Describe how balancing chemical equations supports the Law of Conservation of Mass, using any of the reactions shown in the images.

Open Ended

Explain how the Law of Conservation of Mass is demonstrated in the reaction between hydrogen and oxygen to form water.

Multiple Select

Which of the following are reactants in the process of photosynthesis as shown in the diagram?

• Carbon dioxide

• Water

• Oxygen

• Glucose

Multiple Choice

According to the Law of Conservation of Mass, what is the mass of water produced in the reaction: Ca(OH)2 + 2HCl → CaCl2 + 2H2O, if 18 g of Ca(OH)2 reacts with 17.8 g of HCl to produce 27 g of CaCl2?

• 5.7 g

• 8.8 g

• 9.2 g

• 10.1 g

Open Ended

After learning about the conservation of mass and observing the chemical reaction in the experiment, how do you think the law of conservation of mass applies to real-life situations or other scientific processes?

Open Ended

What is the law of conservation of mass?

Open Ended

Explain why the coefficients in the balanced chemical equation 2Al + 6HCl → 2AlCl₃ + 3H₂ are necessary according to the Law of Conservation of Mass.