1. D. In a chemical reaction, the mass and atoms transferred over must be the same on both sides. Therefore, option D is the correct answer for this question. Since the chemical equation is balanced, the terms and figures on each sides must also be equal.
2. E. Gaseous water is filled with water vapor which will cause the bubbles to rise in the water.
4. B. After dissolving the 1 pound of salt to the 20 pounds of water, you simply add the numbers up to find the combined weight of the two.
5. D. Since there was originally six S atoms in the original equation, two of them are left out in the final diagram since only 4 need to be used to balance out the equation.
6. E. As the water evaporated, the majority of the molecules left while a only a few remain.
7. B. The part of the match that burns remains as the same amount of matter that it was before the match was struck.
9. C. The equation shows us that combining the hydrogen and oxygen bonds help make the hydrogen-oxygen bonds needed to release energy.
11. A. Although the size of the aluminum has changed, the density/mass of each cubic center has not changed.
12. C. Once again a simple addition problem, the gas remains in the tube and the mass would simply be both the weight of the tube itself and the iodine inside added together.
13. B. The mass remains in the tube; therefore, the mass remains the same inside the tube.
17. A. The water received a larger amount of energy than the alcohol since it was heated for a longer period of time and water needs a greater temperature to reach 50o.
18. B. Water has a higher boiling point which makes it take a longer amount of time in order to heat up.
20. B. As more salt is dissolved, more solid salt is deposited at the bottom of the concentration of solution.
21. C. Solid sulfur (S) combines with oxygen (O2) to become sulfur dioxide (SO2).
22. A. Initially, the plate warns up the ice and water to no avail but after a period of time, the plate begins to warm and the temperature increases.
23. B. The heat first dissolves into the environment but after a period of time, the heat from the hot plate goes to the ice and water and heats it up.
24. D. The heat makes the aluminum’s temperature rise at a constant rate.
25. D. Since the aluminum particles are closely held together, the rate of temperature increase is consistent.
27. E. Energy from outside of the cup flows through the styrofoam and copper cup in order to cool down to liquid inside the copper cup.
