Combustion Reactions?
Unlike most metals, gold is found in nature as the pure element. Miners in California in 1849 searched for gold nuggets and gold dust in stream beds, where the denser gold could be easily separated from sand and gravel. However, larger deposits of gold are found in veins of rock and can be separated chemically in a 2-step process:
(1) 4 Au + 8 NaCn + O2 + H2O –> 4 NaAu(CN)2 + 4 NaOH
(2) 2 NaAu(CN)2 + Zn –> 2 Au + Na2[Zn(CN)4]
If a 1000-kilogram sample of rock is 0.019% gold by mass, how much zinc is needed to react with the gold extracted from the rock? Assume that the reaction is 100% efficient.
Thank you 
0.019 : 100 = x : 1000000
x = mass Au = 190 g
moles Au = 190/196.967 g/mol=0.965
moles NaAu(CN)2 = 0.965
moles Zn = 0.965/2=0.482
mass Zn = 0.482 x 65.39=31.5 g
Big Gold Nuggets – Gold Nugget Hunting!
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Gold Mines in North Carolina (Images of America Series) $21.99 The first gold discovery in the United States occurred in 1799 when young Conrad Reed went fishing in Little Meadow Creek in Cabarrus County, North Carolina. The 17-pound nugget he found was used by his family as a doorstop until they figured out what the strange rock was. This chance discovery set off the first gold rush in the nation’s history. For more than a century, men extracted gold from the rolling hills and valleys of the North Carolina piedmont, as well as from the high peaks and rugged mountains of the western part of the state. Prior to the California Gold Rush of 1849, North Carolina led the nation in production of this precious metal and was the largest gold-producing state in the South well into the 20th century. |
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Transportation in Sierra County, California: Roads in Sierra County, California, U.S. Route 395 in California, Interstate 80 in California $13.91 Purchase includes free access to book updates online and a free trial membership in the publisher’s book club where you can select from more than a million books without charge. Chapters: Roads in Sierra County, California, U.s. Route 395 in California, Interstate 80 in California, California State Route 49, California State Route 89. Excerpt: State Route 49 crossing the American River North/Middle Fork, as seen from Foresthill Bridge (the SR-49 bridge is unseen)The South Fork of the Yuba River as it intersects with Hwy 49State Route 49 is a north south state highway in the U.S. state of California that passes through many historic mining communities of the 1849 California gold rush . Highway 49 is numbered after the “49ers”, the waves of immigrants who swept into the area looking for gold, and a portion of it is known as the Gold Country Highway . This roadway begins at Oakhurst , Madera County , in the Sierra Nevada Mountains , where it diverges from State Route 41. It continues in a generally northwest direction, weaving through the communities of Goldside and Ahwahnee, before crossing into Mariposa County . State Route 49 then continues northward through the counties of Tuolumne , Calaveras , Amador , El Dorado , Placer , Nevada , Yuba , Sierra , and Plumas , where it reaches its northern terminus at State Route 70 , in Vinton .This route is part of the California Freeway and Expressway System and is eligible for the State Scenic Highway System .Route description Listed in order from south to north. item Robinson’s Ferry (California Historical Landmark #276, postmile CAL 0.6), a ferry across the Stanislaus River established in 1848. item Birthplace of Archie Stevenot (CHL #769, postmile CAL 3.3), who helped found the California State Chamber of Commerce and was officially named “Mr. Mother Lode” by the California legislature. item Carson Hill (CHL #274, postmile CAL 3.3), where the largest gold nugget in California (195 pounds troy ) was found. item |