Samantha's Chemistry Blog

Exploring Changes of Matter Which examples of matter were chemical and physical ? The task was to carry out and observe 5 scenarios, then determine if a physical or chemical change occurred. The first was to mix 100g of water (H2O) and salt (NaCI) together. The second, we heated up a copper wire in a crucible over fire. The third, was to put 5 drops of sodium hydroxide (NaOH) and 5 drops of copper nitrate (Cu(NO3)2). Fourth, we put 5 drops pf hydrochloric acid (HCI) in 2g of sodium bicarbonate (NaHCO3). Then finally, we subjected paraffin wax to heat in a hot water bath. After conducting each experiment , we then recorded each scenarios reaction beside its procedure to later discuss. -100g of water mixed with 5g of table salt: Turned to salt water and looked foggy -A small wad of copper wire is placed in a crucible and heated: Copper turns to black -5 drops of sodium hydroxide with 5 drops of copper nitrate: Change in state/Composition (jelly) -5 drops of hydrochloric acid ad

3 Question Blog   1. What tasks have you completed recently?        We have completed a total of four tasks the past three weeks in class. The first lab was Exploring        Measurement in the Food Industry, where we determined accuracy and precision after collecting          data for several bags. The second was practicing and learning the importance of significant                  digits. We copied notes and learned what made a measurement more precise or invalid. Third, we        had a Density Lab to find  the density of pennies in water. Then lastly, we worked to solve for the        thickness of aluminum foil by calculating its density, volume and area. 2. What have you learned recently?       I have recently learned how many significant digits are calculated when either adding/subtracting      or multiplying/dividing. I've became familiar with the difference between accuracy and precision        in measurements. Although, its still fresh I have also learned how to fin