2. Max Recorded the Notes Below As He Completed an Experiment in Science Class

Standard 8.P.1.4 #1

1. A water molecule forms when one atom of oxygen combines with two atoms of hydrogen. How many atoms will be present in the molecule that results from the reaction?

A. 1

B. 3

C. 5

D. 6

2. Max recorded the notes below as he completed an experiment in science class.

20 grams of a solute was added to 100 grams of a liquid substance.

The solute completely dissolved.

The total mass of the resulting solution was 120 grams after the experiment was complete.

Which best explains how the law of conservation of mass was demonstrated in the experiment?

A. The solute completely dissolved in the liquid.

B. The liquid was chemically changed by the addition of the solute.

C. Some of the mass of the solute was lost during the experiment.

D. The mass of the resulting solution was equal to the mass of the solute and liquid.

3. When vinegar and baking soda are combined, a mixture is produced, and a gas is released. Which statement is true?

A. The mass of the gas is equal to the mass of the vinegar and baking soda.

B. The mass of the gas is greater than the mass of the vinegar and baking soda.

C. The mass of the mixture and gas is equal to the mass of the vinegar and baking soda.

D. The mass of the mixture and gas is greater than the mass of the vinegar and baking soda.

4. When 15 grams of zinc are combined with 20 grams of hydrochloric acid, two new products are created. What will be the combined weight of the products?

A. 5 grams

B. 15 grams

C. 20 grams

D. 35 grams

5. Which best explains how the chemical reaction shown below follows the law of conservation of mass?

2H2 + O2 → 2H2O

A. The hydrogen and oxygen molecules combine to form water.

B. Hydrogen and oxygen are held together by strong chemical bonds.

C. There are hydrogen and oxygen atoms on both sides of the equation.

D. The same number of hydrogen and oxygen atoms are on both sides of the equation.

6. A chemical reaction occurs in a sealed test tube. As the result of the reaction, 24 grams of product are produced. Which is most likely true?

A. The mass of the reactants was 24 grams.

B. The mass of the reactants was less than 24 grams.

C. The mass of the reactants was more than 24 grams.

D. The mass of the reactants is not related to the 24 grams of product.

7. A sealed test tube containing 8 grams of iron filings and 5 grams of sulfur is heated until the material in the test tube glows bright red. Which is true about the reaction?

A. The product will have a mass of 13 grams.

B. The product will have a mass less than 13 grams.

C. The product will have a mass greater than 13 grams.

D. The mass of the product cannot be determined.

8. If a chemical reaction starts with 10 times the amount of oxygen and hydrogen atoms shown, which best describes the amount of product?

2H2 + O2 → 2H2O

A. There would be 1 less water molecule produced.

B. There would be 10 times more water molecules produced.

C. There would be 20 times more water molecules produced.

D. There would be the same amount of water molecules produced.

9. Sam followed the lab procedures below in completing an experiment.

Place samples of iron filings and sulfur into a test tube.

Cover the test tube with a rubber sheet and seal it.

Measure and record the mass of the test tube and contents.

Heat the test tube until the contents glow red.

Allow the test tube to cool.

After cooling, remeasure and record the mass of the test tube and contents.

Which best describes Sam’s conclusion?

A. A change in mass occurred after heating.

B. No change in mass occurred after heating.

C. A physical change occurred, producing new products.

D. A chemical change occurred, producing new reactants.

10. Element X reacts with element Y to form 250 g of XY. If no reactants are left over, which are most likely the amounts of X and Y in the reaction?

A. 75 g ofX and 175 g of Y

B. 95 g ofX and 115 g of Y

C. 100 g ofX and 200 g of Y

D. 150 g ofX and 300 g of Y