شرح للكيمياء و أسئلة مراجعة

[دلــوعـة أمـهـا]

وداه اسؤال الثاني,,
82. What mass of K2CO3 is needed to prepare 200. mL of a solution having a potassium ion concentration of 0.150 M?
A. 4.15 g
B. 10.4 g
C. 13.8 g
D. 2.07 g
E. 1.49 g



السؤال الثالث,,
84. A 3.682 g sample of potassium chlorate KClO3 is dissolved in enough water to give 375. mL of solution. What is the chlorate ion concentration in this solution?
A. 3.00  10-2 M
B. 4.41  10-2 M
C. 0.118 M
D. 1.65  10-2
E. 8.01  10-2 M


السؤال الرابع,,
85. 25.0 mL of a 0.2450 M NH4Cl solution is added to 55.5 mL of
0.1655 M FeCl3. What is the concentration of chloride ion in the final solution?A. 0.607 M
B. 0.418 M
C. 1.35 M
D. 0.190 M
E. 0.276 M

وآآخر سؤال عارفة إني كلفت عليكم بس ربي إجعلو في موازين حسانتكم,,

90. Reaction of 1.00 mole CH4 with excess Cl2 yields 96.8 g CCl4. What is the percent yield of CCl4 ?(Atomic weights: C = 12.01, Cl = 35.45).
CH4 + 4 Cl2 CCl4 + 4 HCl
A. 64.3
B. 57.3
C. 65.9
D. 62.9