Answer:
0.87 pg
Explanation:
<em>GenAlex Medical, a leading manufacturer of medical laboratory equipment, is designing a new automated system that can detect normal levels of dissolved triiodothyronine (230. to 660 pg/dL), using a blood sample that is as small as 380 μL. Calculate the minimum mass in picograms of triiodothyronine that the new system must be able to detect. Be sure your answer has the correct number of significant digits.</em>
Step 1: Convert 380 μL to deciliters
We will use the following conversion factors.
380 μL × 1 L/10⁶ μL × 10 dL/1 L = 3.8 × 10⁻³ L
Step 2: Calculate the minimum mass of triiodothyronine that can be found in a 3.8 × 10⁻³ L blood sample
Since we are looking for the minimum mass, we will use the lower limit of the concentration interval (230. pg/dL).
3.8 × 10⁻³ L × 230. pg/dL = 0.87 pg
Free electrons tend to go from the negatively charged body to the positively charged body
Adding (S2O3)2- would affect the reaction mechanism that involves this ion. From the reaction mechanism given above, the equilibrium of step 2 would be affected. Adding the stock solution of (S2O3)2- would shift the equilibrium to the right thus making more products of the said mechanism. Also, the reaction rate of this step would occur faster than the original rate. This is based on Le Chatelier's Prinicple which states that a corresponding change would happen to the equilibrium of a reaction when pressure, concentration of the substances or temperature is changed. So, that after the addition, a color change would appear immediately because I3- would be removed slowly from solution, and would therefore be able to react with starch.
Answer:
15.4%
Explanation:
If Ka = 0.54 mM = 1.51x10⁻⁵
Then;
C₄H₈O₂ --------> C₄H₇O₂⁻ + H⁺
I 0.54x10⁻³ 0 0
E 0.54x10⁻³(1-x) 0.54x10⁻³x 0.54x10⁻³x
Recall that x is the percentage degree of dissociation
From the ICE table;
Ka = [C₄H₇O₂⁻] [ H⁺]/[C₄H₈O₂]
1.51x10⁻⁵=(0.54x10⁻³x) (0.54x10⁻³x)/ 0.54x10⁻³(1-x)
1.51x10⁻⁵ = 0.54x10⁻³x^2/1-x
1.51x10⁻⁵(1-x) = 0.54x10⁻³x^2
1.51x10⁻⁵ - 1.51x10⁻⁵x = 0.54x10⁻³x^2
Hence;
0.54x10⁻³x^2 + 1.51x10⁻⁵x - 1.51x10⁻⁵=0
x^2 + 0.028x - 0.028 = 0
Solving the quadratic equation here;
x = 0.154 or −0.182
Ignoring the negative result, x = 0.154
Hence, fraction of butanoic acid that is in the dissociated form in this solution = 15.4%
