4ORCE
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Question # 1
When a solution containing an unknown number of metal ions is treated with dilute HCl, no precipitate forms. The pH is adjusted to about 1, and H2S is bubbled through. Again no precipitate forms. The pH of the solution is then adjusted to about 8 and treated with (NH4)2S. This time a precipitate forms. The filtrate from this solution is not tested. Which groups of metal ions are either known to be present or cannot be excluded?
A. Group III and Group IV
B. Group III only
C. Group II and Group IV
D. Group IV only
E. Group I and Group IV
Question # 2
In the course of various qualitative analysis procedures, the following mixture is encountered: Na+ and K+. Suggest how this mixture might be separated. You may need to refer to Table 4.1 from Zumdahl.
A. add dilute HCl
B. add 0.2 M HCl and H2S
C. add (NH4)2S at pH 8
D. add (NH4)2HPO4 to a basic solution
E. It is not possible to separate the ions using any reaction scheme found in either Zumdahl or your lab manual.
I got D for #1 because the rest will precipitate but then I'm thinking E because only some of the group I ions will precipitate.
For #2 I got E, its not possible because they are always soluble.
Can anyone help?
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Question # 1
When a solution containing an unknown number of metal ions is treated with dilute HCl, no precipitate forms. The pH is adjusted to about 1, and H2S is bubbled through. Again no precipitate forms. The pH of the solution is then adjusted to about 8 and treated with (NH4)2S. This time a precipitate forms. The filtrate from this solution is not tested. Which groups of metal ions are either known to be present or cannot be excluded?
A. Group III and Group IV
B. Group III only
C. Group II and Group IV
D. Group IV only
E. Group I and Group IV
Question # 2
In the course of various qualitative analysis procedures, the following mixture is encountered: Na+ and K+. Suggest how this mixture might be separated. You may need to refer to Table 4.1 from Zumdahl.
A. add dilute HCl
B. add 0.2 M HCl and H2S
C. add (NH4)2S at pH 8
D. add (NH4)2HPO4 to a basic solution
E. It is not possible to separate the ions using any reaction scheme found in either Zumdahl or your lab manual.
I got D for #1 because the rest will precipitate but then I'm thinking E because only some of the group I ions will precipitate.
For #2 I got E, its not possible because they are always soluble.
Can anyone help?
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If y=x + sin(xy) then dy/dx equals....
I don't understand how you take the derivative of sin(xy).
I think you have to use the multiplication rule and get x dy/dx + y
But what do you do from there?
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Hemoglobin and Binding Affinity to Oxygen
in Biology
Posted
In which one of the following situations would you expect hemoglobin to have the lowest binding affinity for oxygen?
a. in your thigh muscle after you have been running for a minute
b. just below the surface of the skin on a cold day
c. in the pulmonary vein
d. in the kidney
e. in the lung
I want to say A but I'm not sure. My reasoning is that the level of DPG is highest during A so the binding affinity for oxygen by hemoglobin is at its lowest.
Am I correct?