The Mole Concept

A mole is the "counting" unit for chemists to calculate the metal contents of ores. Avogadro's number represents one mole and the number is 6.02 x 10²³. The symbol for the unit mole is mol. The molar mass is the mass, usually in grams, of one mole of a substance. To find the molar mass of a compound you need to add up the masses of each element in the compound. After knowing the molar mass of an element you can find the percent composition of the element. 

Unit 1 Sec. C Summary HW 2

6/30/14

11) Most metals oxidize losing one or more electrons.

12) a. The textbook

b. The textbook is a reliable source.

c. No

13) The textbook because it is a reliable source that explain chemistry well.

14) If you collect inaccurate data or information, you may obtain the wrong results.

15) 19.1 million years

16) a. 32g

b. 48g

c. 100g

d. 58g

e. 180g

17) Copper metal and sodium metal have different molar masses.

18) a. One atom

b. 19.6g/39.1g Half of an atom

c. 3.91g/39.1g = 1/10^th of an atom

19) The percent composition of Cu: 91.7% and Ni: 8.3%

20) a. Ag₂S: 247.81g

b. Al₂O₃: 101.96g

c. CaCO₃: 100.09g

Sources and Uses of Metals

The layers of the earth are the atmosphere, hydrosphere, and lithosphere. The atmosphere provides nitrogen, oxygen, neon, and argon and surrounds the earth. The hydrosphere contains water and some dissolved minerals. The lithosphere is the solid part of the earth and provides the greatest variety of chemical resources. In the lithosphere there is the crust, mantle, and core. An ore is a rock or mineral that can be mined and profitable to extract a metal or other material. A deposit is a naturally occurring collection of ores in the lithosphere. A mineral is a naturally occurring solid that contains the element of interest. 

Unit 1 Sec. C Summary HW

6/29/14

1) Atmosphere: nitrogen and oxygen

Hydrosphere: water and dissolved minerals

Lithosphere: petroleum and metal bearing ores

2) a. The three major parts of the lithosphere are the crust, mantle, and core. The crust contains silicates, natural gas, coal, oil, and others. The mantle contains silicates of magnesium and iron. The core contains iron and nitrogen. 

b. The crust

3) a. Peru

b. Chile

c. China

4) China

5) Minerals are naturally occurring solid compounds containing the element of interest and the ore is a rock or mineral that can be mined and you can extract metals or other materials from it.

6) The factors that make it feasible of mining a particular metallic ore at a certain cite are considering the quantity of useful ore, the type of mining and processing needed to remove the metal, how far away it is from the metal refining facilities, and the environmental impact.  

7) The workers needed to see if the mine has useful ore to be reopened and the environmental impact.

8) “Useful ore” means when the mine has metals in good conditions and there is plenty that can be used.

9) Active metals are conductive making it more difficult to process and refine than less active metals.

10) Copper would be the easiest to process because it is less reactive than zinc and magnesium.

Unit 1 Sec. B Summary HW 5

6/26/14

29) Copper metal and copper (II) ions are more similar chemically because copper metal has the ion Cu²⁺ and the copper (II) ion has the ion Cu²⁺ which is the same.

30) The diameter of calcium ion is 205 pm.

31) a. Bromine

b. Silicon

32) The order of the elements in the modern periodic table would be different from Mendeleev’s table and the grouping of the metals, nonmetals, and metalloids would change.

33) The “sacrificial anode” would prevent the metals from reactivity.