1.12 Classify each of the following as a pure substance or a mixture. If a mixture, indicate whether it is homogeneous or heterogeneous: (a) air, (b) tomato juice, (c) iodine crystals, (d) said. homogeneous mixture heterogeneous mixture pure substance heterogeneous mixture
1.14 Give the chemical symbol or name for each of the following elements, as appropriate: (a) carbon, (b) nitrogen, (c) titanium, (d) zinc, (e) iron, (f) P, (g) Ca, (h) He, (i) Pb, (j) Ag.
C
N
Ti
Zn
Fe
Phosphorus
Calcium
Helium
Lead
Silver
1.16 You are hiking in the mountains and find a shiny gold nugget. It might be the element gold, or it might be “fool’s gold,” which is a nickname for iron pyrite, FeS2. What kinds of experiments could be done to determine if …show more content…
1.18 Read the following description of the element zinc and indicate which are physical properties and which are chemical properties. Zinc is a silver-gray—colored metal that melts at 420 oC. When zinc granules are added to dilute sulfuric acid, hydrogen is given off and the metal dissolves. Zinc has a hardness on the Mohs scale of 2.5 and a density of 7.13 g/cm3 at 25 oC. It reacts slowly with oxygen gas at elevated temperatures to form zinc oxide, …show more content…
The following observations are made: (a) The match burns. (b) The metal gets warmer. (c) Water condenses on the metal. (d) Soot (carbon) is deposited on the metal. Which of these occurrences are due to physical changes, and which are due to chemical changes? chemical change physical change physical change chemical change
1.22 Three beakers contain clear, colorless liquids. One beaker contains pure water, another contains salt water, and another contains sugar water. How can you tell which breaker is which? (No tasting allowed!)
You can hear all three of them so the water in each can evaporate, leaving one empty beaker, one filled with salt, and one filled with