Question

19. To prepare 250.0 ml of 2.5 M KCI you will need to dilute_ b) 3.2 mL )78 m volume of 250.0 mL a) 2 mL ml. of 8.0M KCI solution to a )67 mL d) 100 ml 20. The number of grams of KCl (MW 745 g/mol) you need to make 450 ml of a o.45 M solution? e) 0.37 g a)2.72 g b) 0.067 g c) 15.1 g d) 74.5 8 mL. 21. To prepare 0.20M NaOH (40.0 grnol) you will need to dilute 34 g of NaOH to a) 2.6 mL b) 4200 mL c) 170 mL d) 4.2 mL. e) 5900 22. Which of the following atoms has the most negative electron affinity? d) S e) As a) Na b) Cl c)Br

Answer 1

Ans 22. When an atom gains electron an energy change occurs, remember that the definition of electon

8 20. froct se need to kind that haue man do we know thatふlooo mLpdal ution had 0.45 male kel . In 0.2025 hol 15 2lo for fsehareM Naon Solution Na on at o Solution

Affinity, So negetive sign for the electron affinity which shows that energy is released

So to find the ans we should focuse on which atom gets stable and in which case high energy is realesed in Cl and Br we know that they get stable to get an electron but in Br there is bigger size than Cl so its outer most electron not get strong attraction force compare to Cl

So Cl has more negative vale of electron affinity

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