Can someone help me understand where I went wrong on this chemistry problem (answer included)?

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A mixture of 50.0 g of S and 1.00x 10^2 g of Cl2 reacts completely to form S2Cl2 and SCl2. Find the mass of S2Cl2 formed.

CORRECT ANSWER:
19.8 g S2Cl2

MY ANSWER (and how I got it):
step 1: balance equation
3S + 2Cl2 > S2Cl2 + SCl2

step 2: find limiting reactant
50.0 g S * 1 mol S / 32.07 g S * 1 mol S2Cl2 / 3 mol S = .520 mol S2Cl2
1.00*10^2 g Cl2 * 1 mol Cl2 / 70.0 g Cl2 * 1 mol S2Cl2 / 2 mol Cl2 = .705 mol S2Cl2
limiting reactant is 50.0g S and you can make .520 moles of S2Cl2 with it

step 3: Convert moles made with limiting reactant to grams
.520 mol S2Cl2 * 135.04 g S2Cl2 / 1 mol S2Cl2 = 70.2 g S2Cl2

The mass of S2Cl2 formed is 70.2 g

So where did I go wrong?

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@PinkLipstick,

You went wrong in the first step. This is not one reaction equation, it is two.

2S + Cl2 -> S2Cl2
1S + Cl2 -> SCl2

Let X=the amount of S2Cl2 formed and Y=the amount of SCl2.
From the first equation, the amount of Sulfur used is 64X/134 and from the second equation the amount of sulfur used is 32Y/102 so

64x/134 + 32y/102 = 50

Using the same technique for Chlorine,

70x/134 + 70y/102 = 100

Now you have two equations in two variables and you can solve for X. You won't get exactly the right values with the numbers I used because I rounded the atomic mass of S to 32 and the atomic mass of Cl to 35. Put in the correct values and you'll get the exact answer you want.

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Can someone help me understand where I went wrong on this chemistry problem (answer included)?

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