Chemistry Lab Chemical and Physical Properties

Lab # 4 PHYSICAL AND CHEMICAL PROPERTIES PURPOSE To find out which of these substances will cause a physical or chemical change. To document the different physical and chemical changes. DATA SOLUBILITY OR REACTIONSubstancename| Color | Odor | Effect Of heat | Cold H2O| Hot H2O| Litmus Strip | Dilute HCl| Dilute NaOH| Mg| Shinny SilverFlakes| None | Turned darker, less shinny| No change| No change| No change wet dot | Bubbled, steamed, same shape | None| Cu| CopperBe be | None | Turned shinier | No change| No change| No change wet dot| No change | None| Zn| Shinny Silver Pieces| None | Shinier & darker| No change| Less shinny | No change wet dot| Warm steam bubbles dull in color| None| MgO| Off- whitePowder | None | Little darker color| Turned water milky & slightly dissolved| Separated| Red turned blue, blue no change| Hot dissolved turned yellow| None | CuCO3| Light green powder | None | Turned to black powder| Turned water green stayed separate | Separated| No change wet dot| Bubbl ed dissolved turned bright green| Turn blue| Cu(NO3)2| Bright blue crystals| None | Turned turquoise & to a thick liquid| Water light blue, separate | Dissolved, blue water| Blue turned red, red no change| Turned green, stayed separate| None| NaCl| White crystals | None | No change | Stayed separate| Dissolved, water clear| Red no change, blue dark dot| No change separate| None | OBSERVATION I didn’t smell a difference in any except when heated or mixed with HCl. The best changes happened with the HCl, and hot water. It was interesting to see what changed with what and how. CALCULATIONS None CONCLUSION The CuCO3 had the most changes with all the experiments. It was cool to see the chemical and physical changes. I saw color changes and solid to liquid changes. Only three had changes on the litmus paper. There was only one change with the dilute NaOH. The changes were different than I expected physically and chemically. QUESTIONS A.Did you observe any chemical changes in this e xperiment? Yes there were a lot of chemical changes with the HCl, one with the NaOH, and some with heat and hot water. B. What evidence did you use to decide that something was a chemical change? The starting and ending product were different, color change, sound, heat, and gas production. C. Give at least two examples of chemical changes you observed: HCl and CuCO3 turned bright green, NaOH and CuCO3 D. Classify the following properties of sodium metal as physical or chemical: * Silver metallic color: chemical * Turns gray in air: chemical * Melts at 98*C: physical * Reacts explosively with chlorine gas: chemical E.Classify the following changes as physical or chemical : * Water freezes at O*C: physical * Baking soda when combined with vinegar produces bubbles: chemical * Mothballs gradually disappear at room temperature: chemical * Ice cubes in freezer get smaller with time: chemical * Baking soda loses mass as its heated: chemical * Tarnishing of silver: chemical F. How would you show that dissolving table salt is a physical change? When you dissolve salt it is a chemical change because it dissociates in Na+ ions and Cl- ions. But when you remove the water then the salt remains which is physical change. (http://chemistry. about. com/od/matter/a/lsdissolving-salt-in-water-a-chemical-change-orphysical-change. htm )