To extract gold from its ore, the ore is treated with sodium cyanide solution in the presence of oxygen and
water.
4Au(s) + 8NaCN(aq) + O2(g) + 2H2O(1) ►
4NaAu(CN)2(aq) + 4NaOH(aq)
a. Determine the mass of gold that can be extracted if
25.0 g sodium cyanide is used.
b. If the mass of the ore from which the gold was
extracted is 150.0 g, what percentage of the ore is
gold?

calculate how many grams of ammonia can be produced from 4.21 grams of

n2 + 3h2 = 2nh3

my answer:

25.0g n2 x (1 mol/ 28.0gn2) x (2 mol nh3/ 1 mol n2) x (17.0g nh3/ 1 molnh3) = 30.36g n2

25.0g h2 x (1 mol h2/ 2.00g h2) x (2 mol nh3/ 3 mol h2) x (17.0g nh3/ 1 mol nh3) = 141.67g h2

lr = n2

more infor would

a lot

on passing the small ampere of electric current through the tube made of ar and hg of cfl generates uv rays which excites the fluorescent and thus emits the high radiation by consumption of just 5- 12 w in comparison to incandescent light which requires more power such as around 40 - 55 w to lighten.

moreover the life span of fluorescent or cfl is around 8000 h whereas the life span of incandescent is around 1200 h

hence, the building installed with incandescent lights bears more electricity bill.