Color changes gas formation and precipitate formation

Not all of the combinations resulted in chemical reactions. List the reactants of TWO combinations of substances that you believe did NOT result in a chemical reaction or chemical change. Explain your choices. (4 pts) Signs of chemical change visible in this lab are color changes gas formation and precipitate formation. List the reactants of TWO combinations that resulted in color changes. Describe the color changes. (4 pts) When two solutions combine and a solid substance is formed this solid is called a precipitate. In your experiments if the transparent colorless reactant solutions you combined together formed a cloudy chunky or solid product then a precipitate (solid substance) was formed. List the reactants of TWO combinations of substances that you believe formed precipitates. Describe the precipitates (according to color and clarity). (4 pts) Sometimes gases form when substances react. List the reactants of TWO combinations of substances that you believe formed gases. (4 pts) For each combination listed in Question 4 suggest a gas that may have formed. Use what you know about reactants and products in chemical reactions to make your choice(s). Explain your reasoning. (4 pts) If substances are combined and there is no sign of chemical reaction a physical mixture formed instead. In other words the substances mixed together without the atoms of the substances rearranging to form new substances. Such physical mixtures can be homogeneous or heterogeneous. List one combination from the lab that you believe resulted in a physical mixture. Is this mixture heterogeneous or homogeneous? Explain. (4 pts) Identify at least TWO examples of physical changes that you witness during your normal everyday life and explain what evidence there is of the physical change. (4 pts) Identify at least TWO examples of chemical changes that you witness during your normal everyday life and explain what evidence there is of the chemical change. (4 pts) Hydrogen peroxide decomposes in the presence of light which is why it is sold in a dark bottle. The dark bottle prevents light from reaching the hydrogen peroxide and slows its decomposition. Using what you know of decomposition reactions predict the products of the decomposition of hydrogen peroxide (do not look this up—yet!). Explain your choice of products. (2 pts) a. b.Now research and write out the actual products of this decomposition reaction and cite your source. (If they are the same as your choice in Question 9a you must still cite the source that confirms you were correct.) (3 pts) c.Next put the reactants and (correct) products together in a balanced chemical equation. (2 pts) When ammonia (NH3) comes in contact with water (H2O) it forms ammonium hydroxide (NH4OH). This means that an aqueous solution of ammonia (a solution in which water is the solvent is called an aqueous solution) will contain NH4OH. Revisit the reaction between Epsom salt (MgSO4) and ammonia (NH3) and substitute NH4OH as the second reactant in place of ammonia a.Write out the reactants as noted above. What type of chemical reaction do you think reactants of this type (two ionic compounds) are likely to undergo? Explain your choice. (3 pts) b. Predict the products of the reactants in 10a based on the patterns of the reaction type you suggested. (2 pts) c. Write a balanced equation for this reaction. (2 pts) Catalysts increase the rate of chemical reactions without participating in the reaction. This means that catalysts help a reaction along but are not reactants; they remain unchanged throughout a reaction. Biological catalysts also known as enzymes speed up reactions in living cells. One such enzyme is called catalase and is found in potato cells. When food is cooked enzymes can be destroyed. Using the information above explain the differences in your observations of hydrogen peroxide (H2O2) when mixed with cooked and uncooked potatoes. Discuss each combination separately noting whether a reaction occurred and noting the role (if any) of a catalyst a. Uncooked potato and hydrogen peroxide: (3 pts) b. Cooked potato and hydrogen peroxide: (3 pts) Not all of the combinations resulted in chemical reactions. List the reactants of TWO combinations of substances that you believe did NOT result in a chemical reaction or chemical change. Explain your choices. (4 pts)Signs of chemical change visible in this lab are color changes gas formation and precipitate formation. List the reactants of TWO combinations that resulted in color changes. Describe the color changes. (4 pts)When two solutions combine and a solid substance is formed this solid is called a precipitate. In your experiments if the transparent colorless reactant solutions you combined together formed a cloudy chunky or solid product then a precipitate (solid substance) was formed. List the reactants of TWO combinations of substances that you believe formed precipitates. Describe the precipitates (according to color and clarity). (4 pts)Sometimes gases form when substances react. List the reactants of TWO combinations of substances that you believe formed gases. (4 pts)For each combination listed in Question 4 suggest a gas that may have formed. Use what you know about reactants and products in chemical reactions to make your choice(s). Explain your reasoning. (4 pts)If substances are combined and there is no sign of chemical reaction a physical mixture formed instead. In other words the substances mixed together without the atoms of the substances rearranging to form new substances. Such physical mixtures can be homogeneous or heterogeneous.

List one combination from the lab that you believe resulted in a physical mixture. Is this mixture heterogeneous or homogeneous? Explain. (4 pts)Identify at least TWO examples of physical changes that you witness during your normal everyday life and explain what evidence there is of the physical change. (4 pts)Identify at least TWO examples of chemical changes that you witness during your normal everyday life and explain what evidence there is of the chemical change. (4 pts)Hydrogen peroxide decomposes in the presence of light which is why it is sold in a dark bottle. The dark bottle prevents light from reaching the hydrogen peroxide and slows its decomposition. Using what you know of decomposition reactions predict the products of the decomposition of hydrogen peroxide (do not look this up—yet!). Explain your choice of products. (2 pts) a. b.Now research and write out the actual products of this decomposition reaction and cite your source. (If they are the same as your choice in Question 9a you must still cite the source that confirms you were correct.) (3 pts) c.Next put the reactants and (correct) products together in a balanced chemical equation. (2 pts)When ammonia (NH3) comes in contact with water (H2O) it forms ammonium hydroxide (NH4OH). This means that an aqueous solution of ammonia (a solution in which water is the solvent is called an aqueous solution) will contain NH4OH. Revisit the reaction between Epsom salt (MgSO4) and ammonia (NH3) and substitute NH4OH as the second reactant in place of ammonia a.Write out the reactants as noted above. What type of chemical reaction do you think reactants of this type (two ionic compounds) are likely to undergo? Explain your choice. (3 pts) b. Predict the products of the reactants in 10a based on the patterns of the reaction type you suggested. (2 pts)

c. Write a balanced equation for this reaction. (2 pts)Catalysts increase the rate of chemical reactions without participating in the reaction.

This means that catalysts help a reaction along but are not reactants; they remain unchanged throughout a reaction. Biological catalysts also known as enzymes speed up reactions in living cells. One such enzyme is called catalase and is found in potato cells. When food is cooked enzymes can be destroyed. Using the information above explain the differences in your observations of hydrogen peroxide (H2O2) when mixed with cooked and uncooked potatoes. Discuss each combination separately noting whether a reaction occurred and noting the role (if any) of a catalyst

a. Uncooked potato and hydrogen peroxide: (3 pts)

b. Cooked potato and hydrogen peroxide: (3 pts)