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Which of the following represents the electronic configuration of Ca^2*? [Ar]3s^

ID: 1073954 • Letter: W

Question

Which of the following represents the electronic configuration of Ca^2*? [Ar]3s^2 1s^22s^22p^63s^23d^64s^2 [Kr]4s^2 [Ne]3s^2 1s^22s^22p^23s^23p^6 Total combustion of butane (C_4H_10) yields carbon dioxide (CO_2) and water (H_2O). Calculate the number of grams of oxygen (O_2) needed to react completely with 87.0 grams of C_4H_30 first, write a balance equation for this reaction) 290 g 312 g S8 g 208 g 120 g A helium filled balloon is launched from the ground where the pressure is 750 mmHg and the temperature is 21 Degree C. Under these conditions its volume is 75.0 L. When the balloon has climbed to an altitude where the pressure is 89 mmHg and the temperature is 0 Degree C, what Is its volume? 8.24 L 9.561 75.01 5871 682 L Living cells can be kept at isotonic saline (0.15 M NaCl) for hours without damage. If you are asked to prepare a similar isotonic solution with Mg_3(PO_4)2 (magnesium phosphate), what will be the concentration of magnesium phosphate in this solution? (isotonic solutions have the same osmolality). 0.060M 0.075 M 0.15M 0.300M 0.350 M

Explanation / Answer

1. Ca = 20 1s22s22p63s23p64s2

    Ca = 20 [Ar]4s2

Ca ---------> Ca+2 + 2e-

20e-          18e-

Ca+2 = 1s22s22p63s23p6

E. 1s22s22p63s23p6

2. 2C4H10   + 13O2 ---------> 8CO2 + 10H2O

    2 moles of C4H10 react with 13 moles of O2

2*58g of C4H10 react with 13*32g of O2

87g of C4H10 react with = 13*32*87/2*58 = 312g of O2

B. 312g

3.    intial                                                                    final

    P1 = 750mmHg                                                    P2 = 89mmHg

   V1 = 75L                                                                V2 =

   T1 = 21C0   = 21+ 273 = 294K                             T2 = 0C0   = 273K

         P1V1/T1     =     P2V2/T2

              V2         = P1V1T2/T1P2

                          = 750*75*273/294*89   = 587L

D. 587L

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