The answer is c. 5.2 * 10^-5 Ms-1. The rate law for this reaction is given. So you only need to replace the letter with number given. And also calculate the unit. Then you can get answer.
<span>An object at rest will stay at rest unless acted upon by a unbalanced force.
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Answer:
Sodium Sulfide + Silver Nitrate = Sodium Nitrate + Silver Sulfide
Fe 3+ + SCN- --> FeSCN 2+
<span>.......Fe 3+ .......SCN-.........FeSCN 2+ </span>
<span>I.......0.04..........0.001.............. </span>
<span>C........-x...............-x............. </span>
<span>E.....0.04-x.....0.001-x...........x </span>
<span>Keq = 203.4 = x / (0.04-x)(0.001-x) </span>
<span>203.4 = x / (x^2 - 0.041x + 4x10^-5) </span>
<span>203.4x^2 - 8.34x + 0.00094 = x </span>
<span>203.4x^2 - 9.34x + 0.00094 = 0 </span>
<span>x = -0.0001M or 0.0458M </span>
<span>so, using your Keq, there would be no SCN- or Fe 3+ left.....all would be in the form of FeSCN 2+</span>
The +1 is a charge, but really + means minus, and - means addition.