[مـــلآك]

السلام عليكم

عندي سؤالين في شابتر 4 من تست الدكتوره اكرام..


2. A 50.0 mL sample of 0.436 M NH4NO3 is diluted with water to a total volume of 250.0 mL. What is the ammonium nitrate concentration in the resulting solution?

A. 21.8 M
B. 0.459 M
C. 2.18 * 10-2 M
D. 8.72 * 10-2 M
E. 0.109 M

انا عارفه طريقه الحل لكن الجواب طلع لي 0,0875 !



4. What volume, in mL, of a 3.89 x 10-2 M solution is required to provide 2.12 g of KBr?
(Atomic weights: K = 39.10, Br = 79.90).
a) 520
[b) 458
c) 389
d) 325
e) 425