Question

UI LABI 2 4oom 2.2504 405 m2 27) If 850 mL of 1.36 M NH.Cl is diluted to 4.50 L, the concentration of the resulting solution is A) 0.0356 M B) 0.200 M C) 4.00 M D) 40.0 M E) 0.257 M 28) To prepare 25 mL of 0.25 M MgCl, solution from a 0.75 M MgCl, stock solution, you shoul A) 10 mL of stock solution mixed with enough water to make 25 ml B) 12 mL of stock solution mixed with enough water to make 25 ml C) 17 mL of stock solution mixed with enough water to make 25 ml D) 9.6 mL of stock solution mixed with enough water to make 25 mL E) 8.3 mL of stock solution mixed with enough water to make 25 ml 29) What volume, in liters, of 0.150 Ba(OH)2 solution is needed to react completely with 0. 0.300 M HNO, solution according to the equation Ba(OH)2 + 2HNO3 + Ba(NO3)2 + 2H20 A) 0.150 L Ba(OH)2 B) 0.200 L Ba(OH)2 C) 0.300 L Ba(OH)2 D) 0.600 L Ba(OH)2 E) 0.250 L Ba(OH)2
help with 27-29 please

Answer 1

27)

use dilution formula

M1*V1 = M2*V2

1---> is for stock solution

2---> is for diluted solution

Given:

M1 = 1.36 M

V1 = 0.85 L

V2 = 4.5 L

use:

M1*V1 = M2*V2

M2 = (M1*V1)/V2

M2 = (1.36*0.85)/4.5

M2 = 0.257 M

Answer: E

28)

use dilution formula

M1*V1 = M2*V2

1---> is for stock solution

2---> is for diluted solution

Given:

M1 = 0.75 M

M2 = 0.25 M

V2 = 25 mL

use:

M1*V1 = M2*V2

V1 = (M2 * V2) / M1

V1 = (0.25*25)/0.75

V1 = 8.3 mL

Answer: E

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