 Lv 2374 points

# MIHAILO

Questions6
• ### What exactly is the reversible binding of calcium?

What does it mean? Like I know Ca2+ is used for muscle contractions when it attaches to troponin, and that it detaches and makes its way back into the sarcoplasmic reticulum at some point. What does the "reversible binding" concept mean? Can't seem to find a decent answer.

• ### Copper-Ammonia Complex Question?

Consult a table of formation constants and consider the consequences for the copper-ammonia complex equilibrium. Once ammonia solution is added to copper solution and equilibrium is established, the concentration of the uncombined copper is:

-very small compared to the resulting copper amine complex

-equal to the resulting copper amine complex

-zero

-very large compared to the resulting copper amine complex

I looked at a table and found that the constant is 1.1*10^13. How does this help answer the question? Thanks!

• ### Chemistry Equilibrium Question?

“Explain why the assumption [SCN-]=[FeSCN2+] only is used for the prototype”.

This question pertains to an experiment we did in lab. We mixed Fe3 and SCN so we could calculate the absorbance through spectrophotometry and finding the Keq. I don’t understand the question they are asking us above. Help?

• ### Strange Volume Question (chemistry)?

Suppose one needed 9.73 grams of dilute aqueous solution. What is the approximate volume of the solution in mL that would be equivalent to that number of grams?

Would this be 973mL, since it is grams per 100mL of water?

• ### What are the approximate bond angles for HNO2?

This is a little bit of a tough one for me. It wants me to find the bond angles for 1 and 2. I figured out that N would be the central atom since that is the least electronegative atom (right?). There are three electron regions on N, and four electron regions on O. Wouldn't the answer be 1(90) and 2(120)? It wants me to do it to FOUR significant figures, and I can't really figure out how to get that many numbers. Thanks!

• ### What is the CONDENSED electron configuration for Y^3+?

Hi pisgahchemist! I'm sure you'll see this first, and sorry for asking something again.

So I was asked to find the condensed electron configuration for Y3+. Now obviously I know that the standard condensed for Y is [Kr] 5s2 4d1. Since you're supposed to subtract 3 (starting from s and moving to d) I get [Kr] 5s0 4d0, or just [Kr]. Neither of these answers work, and I was wondering why. Thanks!

• ### Detailed calculations show that the value of Zeff for the outermost electrons in Si and Cl atoms is 4.29+ and 6.12+ , respectively.?

What value do you estimate for Zeff experienced by the outermost electron in both Si and Cl, assuming that core electrons contribute 1.00 and valence electrons contribute 0.00 to the screening constant?

-So, I know the equation to this is Zeff=Z-S, where Z is the number of protons and S is the nuclear shielding. For Si, shouldn't this be 2, and for Cl, 5? This doesn't work, and it's puzzling me. Thanks!

• ### Should I date this woman?

So she seems super sweet but I'm just not sure if she really likes me or she's just using me. Last semester she asked me the day before finals if she wanted to go out on a date. When I got to the cafe she asked if I could help her with her math homework (which had to be done before or she would fail). I did all her work for her (which took a good five to six hours) because I felt bad for her. She left as soon as I finished and we never got a chance to talk or anything. I haven't gotten text from her until the semester started up again and shes asking me out again. What should I do? I feel really bad for her.