(Pages 357-363) When speaking of change, chemists refer to the system and the surroundings. Together, the system and the surroundings make up the universe. You choose the system that you want to investigate and you can imagine drawing a dashed surface around the system, to separate it from the surroundings. When considering change you think […]Read more "Chem Talk #8"
(Pages 345-349) In this section we explore a chemical reaction that continues to occur on its own once it begins. This reaction is called spontaneous. In a case of a reaction that produces heat energy, controlling the speed of the reaction will let you control how quickly heat is produced. For chemists and engineers to […]Read more "Chem Talk #7"
(Page 340-341) Only the 0.1 M of ZN (NO3)2 was conductive and we could tell because it was the only solution that made the LED light. d because it has an ion in it which is what you need to conduct electricity a. it would be dangerous because tap water can conduct electricity which would […]Read more "Chem To Go #6"
(Pages 336-338) Substances that dissolve in water to make solutions that conduct electricity are called electrolytes. In this invention we used a conductivity tester to determine if a solution conducted electricity. For any solution to be able to conduct electricity, it must contain charged particles that are able to move. Al the solutions we tested […]Read more "Chem Talk #6"
(Pages 326-329) In this investigation we examined the colors that make up visible light and used LEDs to explore a glow-in-the-dark star. Light is a form of energy known as electromagnetic radiation. Electromagnetic radiation includes X-rays, ultraviolets (UV) rays, microwaves, and radio waves in addition to visible light. The electromagnetic spectrum (a list of electromagnetic […]Read more "Chem talk #5"
(Pages 316-318) Metals are shiny (or can be polished to shine). They can also conduct electricity, so they are used in electrical circuits. They conduct heat, so they are used in cookware. Since most metals can withstand high temperatures, they are used to build strong structures. They are malleable and are pounded into different shapes […]Read more "Chem Talk #4"
(Pages 308-309) 1 a. CO2 b. The seltzer water with heat c. The reaction would not be complete if both materials were not there in the beginning. d. Yes, it does matter how much of the starting material was available. 2. NaHCO3 + HC2H3O2 —> NaC2H3O2 +H2O + CO2 (23+1+12) + (1+24+3+32) —> (23+24+3+32) + […]Read more "Chem To Go #3"
(Pages 303-307) A mole is a counting word used to count very large quantities of very small objects (mainly atoms and molecules). 1 mole= 6.022 * 10^23. Three moles of something is three times as much as one mole. One mole of a single kind of atom or molecule has a mass equal to its […]Read more "Chem Talk #3"
(Page 288) 1. a. exothermic because the tablet is releasing energy while the water is absorbing it b. exothermic because when water goes from a gas to a liquid it releases energy c. endothermic because the oxidation is the lost of energy and the copper is gaining the energy 2. a. the disorder is […]Read more "Chem To Go #1"