Answer:
<u>5 moles S x (36.02 g S/mole S) = 180.1 grams of S</u>
Explanation:
The periodic table has mass units for every element that can be correlated with the number of atoms of that element. The relationship is known as Avogadro's Number. This number, 6.02x
, is nicknamed the mole, which scientists found to be a lot more catchy, and easier to write than 6.02x. <u>The mole is correlated to the atomic mass of that element.</u> The atomic mass of sulfur, S, is 36.02 AMU, atomic mass units. <u>But it can also be read as 36.02 grams/mole.</u>
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<u>This means that 36.02 grams of S contains 1 mole (6.02x</u><u>) of S atoms</u>.
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This relationship holds for all the elements. Zinc, Zn, has an atomic mass of 65.38 AMU, so it has a "molar mass" of 65.38 grams/mole. ^5.38 grams of Zn contains 1 mole of Zn atoms.
And so on.
5.0 moles of Sulfur would therefore contain:
(5.0 moles S)*(36.02 grams/mole S) = <u>180.1 grams of S</u>
Note how the units cancel to leaves just grams. The units are extremely helpful in mole calculations to insure the correct mathematical operation is done. To find the number of moles in 70 g of S, for example, we would write:
(70g S)/(36.02 grams S/mole S) = 1.94 moles of S. [<u>Note how the units cancel to leave just moles</u>]
For the desired pH of 5.76, 0.365 mol of acetate and 0.035 mol of acid are to be added
let the concentration of acetate be x
then the concentration of acid will be (0.8 - x)
pKa of acetate buffer = 4.76
pH = pKa + log([acetate]/[acid])
⇒4.76 = 4.76 + log(x/(0.8-x))
⇒log(x/(0.8-x)) = 0
⇒x/(0.8-x) = 1
⇒x = 0.4
Therefore
[acetate] = x = 0.4
[acid] = 0.8-x =0.4 M
number of mol = concentration *(volume in mL)
number of mol of acetate = 0.4*0.5
= 0.20 mol
number of mol acid = 0.4*0.5
= 0.20 mol
when desired pH = 5.76
pH = pKa + log([acetate]/[acid])
⇒5.76 = 4.76 + log(x/(0.8-x))
⇒log(x/(0.8-x)) = 1
⇒x/(0.8-x) = 10
⇒x = 8 - 10x
⇒x = 8/11
⇒x= 0.73
[acetate] = x= 0.73
[acid] = 0.8-x = 0.07 M
number of mol = concentration * (volume in mL)
number of mol acetate to be added = 0.73*0.5 = 0.365 mol
number of mol acid to be added = 0.07*0.5 = 0.035 mol
Problem based on acetic acid required to maintain a certain pH
brainly.com/question/9240031
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C (s) + 2 H2 (g) = CH4 (g)
