NAME: TOTAL /25 1. A hot pack contains chemicals that can be activated to produce heat. A cold pack contains chemicals that feel cold when activated. Figure 1 Describe how the Law of Conservation of Energy applies to the chemical reaction that occurs in the hot pack. 2. Base your answer to the question on the particle diagrams, which show atoms and/or molecules in three different samples of matter at STP. Explain why does not represent a compound. 3. Base your answer on the balanced chemical equation: What type of reaction does this equation represent? castlelearning.com/ /AssignmentPrinti 1/6
4. Base your answer to the question on the particle diagrams. Samples A, B, and C contain molecules at STP. Figure 2 Explain why sample C could represent a mixture of fluorine and hydrogen chloride. 5. [Refer to figure 2 in question 4] Contrast sample A and sample B, in terms of compounds and mixtures. Include both sample A and sample B in your answer. 6. A scientist in a chemistry laboratory determined the molecular formulas for two compounds containing nitrogen and oxygen to be NO 2 and N 2 O 5. Write an IUPAC name for the compound N 2 O 5. Figure 3 castlelearning.com/ /AssignmentPrinti 2/6
7. A student places a 2.50-gram sample of magnesium metal in a bottle and fits the bottle with a 2-hole stopper as shown in the diagram. Hydrochloric acid is added to the bottle, causing a reaction. As the reaction proceeds, hydrogen gas travels through the tubing to an inverted bottle filled with water, displacing some of the water in the bottle. Figure 4 Identify the type of chemical reaction that occurs when magnesium reacts with hydrochloric acid. castlelearning.com/ /AssignmentPrinti 3/6
8. The particle diagrams below represent the reaction between two nonmetals, A 2 and Q 2 Figure 5 Compare the total mass of the reactants to the total mass of the product. 9. Base your answer to this question on the information below. Rust on an automobile door contains Fe 2 O(s). The balanced equation representing one of the reactions between iron in the door of the automobile and oxygen in the atmosphere is given below. 4Fe(s) + 3O 2 (g) 2Fe 2 O 3 (s) Figure 6 Identify the type of chemical reaction represented by this equation. 10. Write the empirical formula for the compound C 8 H 18. castlelearning.com/ /AssignmentPrinti 4/6
11. Some dry chemicals can be used to put out forest fires. One of these chemicals is NaHCO 3. When NaHCO 3 (s) is heated, one of the products is CO 2 (g), as shown in the balanced equation below. 2NaHCO 3 (s) + heat Na 2 CO 3 (s) + H 2 O(g) + CO 2 (g) Figure 7 Identify the type of chemical reaction represented by this equation. 12. In an investigation, a dripless wax candle is massed and then lighted. As the candle burns, a small amount of liquid wax forms near the flame. After 10 minutes, the candle s flame is extinguished and the candle is allowed to cool. The cooled candle is massed. Figure 8 State one observation that indicates a chemical change has occurred in this investigation. 13. A fluorescent light tube contains a noble gas and a drop of mercury. When the fluorescent light operates, the Hg is a vapor and there are free-flowing Hg ions and electrons in the tube. The electrons collide with Hg atoms that then emit ultraviolet (UV) radiation. The inside of the tube is coated with a mixture of several compounds that absorbs UV radiation. Ions in the coating emit a blend of red, green, and blue light that together appears as white light. The compound that produces red light is Y 2 O 3. The compound that produces green light is CeMgAl 11 O 19. The compound that produces blue light is BaMgAl 10 O 17. Figure 9 Write the chemical name of the compound that produces red light. castlelearning.com/ /AssignmentPrinti 5/6
14. Base your answer to this question on the information below. The Solvay process is a multistep industrial process used to produce washing soda, Na 2 CO 3 (s). In the last step of the Solvay process, NaHCO 3 (s) is heated to 300 C, producing washing soda, water, and carbon dioxide. This reaction is represented by the balanced equation below. 2NaHCO 3 (s) + heat Na 2 CO 3 (s) + H 2 O(g) + CO 2 (g) Write the IUPAC name for washing soda. Figure 10 15. Base your answer to this question on the information below. A tablet of one antacid contains citric acid, H 3 C 6 H 5 O 7, and sodium hydrogen carbonate, NaHCO 3. When the tablet dissolves in water, bubbles of CO 2 are produced. This reaction is represented by the incomplete equation below. H 3 C 6 H 5 O 7 (aq) + 3NaHCO 3 (aq) Na 3 C 6 H 5 O 7 (aq) + 3CO 2 (g) + 3 ( ) Figure 11 State evidence that a chemical reaction occurred when the tablet was placed in the water. castlelearning.com/ /AssignmentPrinti 6/6