AboutPhilip Carlson Ph.D. (Cand.) Expertise Prefer questions regarding general chemistry, analytical chemistry, and physical chemistry. Have less knowledge about organic chemistry but can help with most undergraduate organic chemistry questions not related to reactions and their mechanisms.
Experience Highly experienced in physical chemistry both theoretical and experimental. Current research focus is fluorescence spectroscopy and electronic structure theory (e.g. quantum mechanics). Past research focus was in analytical chemistry in the area of photocatalysis.
Organizations American Chemical Society;
Society of Christian Philosophers;
Evangelical Philosophical Society
Publications Lori A. Pretzer, Philp J. Carlson, and Joel E. Boyd. "The effect of Pt oxidation state and concentration on the photocatalytic removal of aqueous ammonia with Pt-modified titania." J. Photochem. Photobiol. A: Chemistry. 200 (2008) 246-253. ;
Philip J. Carlson, Lori A. Pretzer, and Joel E. Boyd. "Solvent Deposition of titanium dioxide on acrylic for photocatalytic application." Ind. Eng. Chem. Res. 46 (2007) 7970-7976.
Education/Credentials A.S. in Chemistry from Garden City Community College, Garden City, KS;
B.S. in Mathematics from Wayland Baptist University, Plainview, TX;
B.S. in Chemistry from Wayland Baptist University, Plainview, TX;
Ph.D. (Cand.) in Physical Chemistry at Iowa State University, Ames, IA;
B.A. in Evangelism and Missions;
M.A. in Theological studies (In progress) from Louisiana Baptist University
Question Hey I've been stuck on this question for over 2 hours from an old test of one of my professors.
Elemental sulphur (s) can be obtained from hydrogen sulphide (H2S) through reaction with sulphur dioxide (SO2).
2 H2S(g) + S02(g) ----> 3 S(s) + 2 H20(l)
Determine what mass of sulphur is produced when 8.18 g of hydrogen sulphide (H2S) is reacted with a 4.01L sample of sulphur dioxide (SO2) held at 725 torr and 295 K.
R= 62.364 L Torr mol^-1 K^-1
T=295 degrees celcius
PV=nRT
The answer to it is 11.5g and i just cant come up with it. Really appreciate it if you're able to solve it so i don't have to go try to get in contact with my professor.
Thanks a lot.
Answer Hey Roshanb,
I sat down and worked it through and arrived at 11.52g as the answer. Let me walk you through it.
First this problem involves gases and it also involves determining products. Any problem where you are asked how much of a product can you produce you need to determine the limiting reactant (aka limiting reagent). In order to determine what limits how much S I can produce I need to find out how many moles of each reactant I have. Why? That is because I only know how the moles of each thing are related. from the chemical reaction you wrote I know that for every 2 mol of H2S and 1 mol of SO2 I can make 3 mol of S and 2 mol H2O. Since I know how those relate only by moles I need to find out how many moles of each reactant I have. So since H2S is in grams it will be easier than SO2. Let's start there then.
For H2S:
8.18g H2S(1mol/34g H2S)=0.24mol H2S
Now for SO2:
Since we only know the volume of this that we have we need to use the ideal gas equation to find the number of moles. PV/RT=n
((725Torr)(4.01L))/((62.364)(295K))=0.158mol SO2
Now that you know how many moles of each reactant you have you need to determine which one limits how much products you can produce.
So for each 2 mol of H2S we need 1 mol of SO2 so take
0.24mol H2S(1molSO2/2molH2S)=0.12mol SO2 so to react with all 0.24mol of H2S you need 0.12mol SO2 which you have!!!
Now for SO2:
0.158mol SO2(2molH2S/1molSO2)=0.316mol H2S required. This is more than you have. :-( so this means that you limiting reagent is H2S!
Since H2S is your limiting reactant we will use it to determine how much products we can make.
0.24mol H2S (3mol S/2mol H2S)=0.36mol S
If we use all 0.24mol H2S we can make 0.36mol S, but how many grams is that?
0.36mol S(32g/1molS)=11.52g S
Hence you can make 11.52g of Sulfur with this reaction. There are however, a number of assumptions that went into this process which would cause error if you were to do this in the lab. Basically what I am saying is if you were to do this experiment in the lab you probably would not get 11.52g S at the end. But hey all we were asked to do was calculate it.
