3.14 - Review

1. Give a method that would separate each mixture: a. sand and baking soda c. the components of ink Dissolve baking soda Use Chromotography in water and use filter   b. alcohol and water d. iron filings and salt  Boil off the alcohol Use a magnet to remove iron

2. Name the 7 elements that exist as diatomic molecules when pure: Bromine, Iodine, Nitrogen, Chlorine, Hydrogen, Oxygen Fluorine

3. Do all elements have the same number of atoms per mole. Yes Explain 3. Do all elements have the same number of atoms per mole? Yes Explain. The mole is a defined number, like a dozen. 6.02x1023

4. Identify these properties as intensive or extensive: a. boiling point – intensive b. density - intensive c. conductivity - intensice d. solubility in water - intensive e. mass - extensive f. volume - extensive g. color - intensive h. heat content - extensive i. melting point - intensive

5. Processes in nature move toward low energy and high entropy.  

6. The basic unit of an element is the atom and the basic unit of a compound is the molecule.

7. There are 3 major differences between mixtures and compounds 7. There are 3 major differences between mixtures and compounds. They are: 1. Compounds are bonded together 2. elements in a compound do not retain their properties. 3. Componds have a definite composition.

8. Describe how you would separate a mixture of sand and sugar. Mix with water. Sugar will dissolve. Filter out the sand.

9. Co represents Cobalt and CO represents Carbon Monoxide.

10. Distinguish between an exothermic and an endothermic process 10. Distinguish between an exothermic and an endothermic process. Give an example of each. Exothermic – heat exits or leaves the reaction – a lit match Endothermic – heat enters the reaction – a chemical cold pack

b. Name three kinds of materials that are homogeneous. 11. a. What does homogeneous mean? The same throughout, evenly distribution   b. Name three kinds of materials that are homogeneous. Solutions, alloys, amalgams

12. Identify each of the following as a physical (P), chemical (C) or nuclear (N) change: sulfur dissolves in carbon disulfide P f. milk sours C a needle is magnetized P g. uranium decays into thorium N limestone is crushed P h. steam is formed from water P carbon transformation into nitrogen N i. copper conducts electricity P food is cooked C j. an alloy, sterling silver, is formed P

13. Define: Available in the notes Entropy -   substance kinetic energy and potential energy element compound solvent solute amalgam

14. Give 4 indications that a chemical change is taking place 1. production of a gas 2. Production of a solid(precipitate) 3. Production of heat and light 4. Color Change

15. Name these elements: Fe - Iron Mn - Manganese Ra - Radium Pt - Platinum Cs - Cesium

16. Give the symbol: mercury sodium tin scandium gold Hg Na Sn Sc Au phosphorus calcium strontium copper silver P Ca Sr Cu Ag

17. Classify as a heterogeneous mixture, element, compound, or solution (homogeneous mixture). a. nitrogen element b. 14k gold jewelry homogeneous mixtures c. brass homogeneous mixture d. beef stew heterogeneous mixture  e. air homogeneous mixture f. antimony element g. sodium chloride compound h. dental amalgam homogeneous mixture

18. Draw a warming curve for lead, which has a melting point of 327 18. Draw a warming curve for lead, which has a melting point of 327.5C and a boiling point of 1740C.  

19. Give the percent composition of Ca(NO3)2

20. Perform the following mole calculations 95.3 grams Determine the number of grams in 3.92 moles of magnesium     95.3 grams Determine the number of moles in 124.8 g of oxygen gas.  3.9 moles How many atoms are in 4.6 moles of calcium?  2.8 x 1024 Change 23.8 grams of NH3 into number of molecules. 8.43 x 1023

What is the mass in grams of 1.34 x 1024 atoms of zinc?    146 grams What is the mass of 1 atom of tungsten in grams?  3.05 x 10-22 How many atoms oxygen are in 97.0 grams of carbon dioxide, CO2?  2.65 x 1024  How many calcium ions are in a 100. gram sample of calcium phosphate, Ca3(PO4)2? 5.82 x 1023

Larry and Louise performed the water experiment with these results:   mass of cup with water 63.49 g mass of cup and water after sipping 41.33 g   Calculate the number of molecules of water in the sip. 7.4 x 1023

Extra: A drop of water containing 3.4 x 1021 molecules evaporates in 5.5 hours. How many molecules are evaporating per second? 1.7 x 1017