How many grams of Au2S can be obtained from 1017 mol of Au? The answer is 249. How did they get that?
I must admit that I didn't understand the question and had to work it backwards.
Start from a balanced equation
2Au + S -> Au2S
if we are starting with 1.17 mol Au (rather than 1017 mol Au which is rather a lot!)
then as 2 moles of Au give 1 mole of Au2S from the equation, 1.17 mol Au will yield 0.585 mol Au2S.
The molar mass for Au2S is 426 g mol^-1, then the mass obtained is
0.585 mol^-1 x 426 g mol^-1 = 249 g
I don't know how they got that, there could have been a number of ways. One way is to find the percent of Au in Au2S
percentAu= atomicmassAu/molemassAu2S
Then, 1017moleAu/percentAu * atomicmassAu/1 mole
To find the number of grams of Au2S that can be obtained from 1017 mol of Au, we need to use the stoichiometry of the reaction between Au and Au2S.
The balanced chemical equation for the reaction between Au and Au2S is:
2Au + Au2S => 4AuS
From the equation, we can see that 2 moles of Au react with 1 mole of Au2S to form 4 moles of AuS.
To determine the number of moles of Au2S that can be obtained, we need to set up a ratio using the stoichiometry.
Given that we have 1017 moles of Au, we can setup the following ratio:
2 mol Au / 1 mol Au2S = 1017 mol Au / x mol Au2S
Cross-multiplying, we get:
2 mol Au * x mol Au2S = 1 mol Au2S * 1017 mol Au
Simplifying the equation:
2x mol Au2S = 1017 mol Au
Dividing both sides by 2, we get:
x = 1017 mol Au / 2
x = 508.5 mol Au2S
To convert the moles of Au2S to grams, we need to multiply the moles by the molar mass of Au2S.
The molar mass of Au2S can be calculated by adding up the atomic masses of gold (Au) and sulfur (S).
The atomic mass of Au is 196.97 g/mol, and the atomic mass of S is 32.07 g/mol.
2(196.97 g/mol Au) + 32.07 g/mol S = 429.01 g/mol Au2S
Now, we can calculate the number of grams of Au2S:
508.5 mol Au2S * 429.01 g/mol Au2S = 218,296.385 g Au2S
Rounding to the nearest whole number, we get 218,296 g Au2S. Thus, the answer is not 249 grams as stated before, but rather 218,296 grams of Au2S.
To find the number of grams of Au2S that can be obtained from 1017 mol of Au, you need to use the molar ratio between Au2S and Au, along with the molar mass of Au2S.
First, let's determine the molar mass of Au2S. The atomic mass of gold (Au) is approximately 196.97 g/mol, and the atomic mass of sulfur (S) is approximately 32.06 g/mol. Since there are two Au atoms and one S atom in Au2S, the molar mass of Au2S is:
(2 * 196.97 g/mol Au) + (1 * 32.06 g/mol S) = 393.00 g/mol Au2S
Next, we can set up a conversion factor using the molar ratio between Au and Au2S. From the balanced equation of the reaction, we know that 2 mol of Au react with 1 mol of Au2S. Therefore, the molar ratio is:
2 mol Au / 1 mol Au2S
Finally, we can calculate the mass of Au2S using the following steps:
Step 1: Convert the given amount of moles of Au to moles of Au2S using the molar ratio:
1017 mol Au * (1 mol Au2S / 2 mol Au) = 508.5 mol Au2S
Step 2: Convert the moles of Au2S to grams using the molar mass:
508.5 mol Au2S * (393.00 g Au2S / 1 mol Au2S) = 199,900.5 g Au2S
Therefore, the answer should be 199,900.5 grams of Au2S, not 249 grams as you mentioned. Please recheck the given answer.