The half-life of 131I is 0.220 years. How much of a 500.0 mg ...

[WWatsford]

The half-life of 131I is 0.220 years. How much of a 500.0 mg sample remains after 24 hours?
 
  A) 496 mg
  B) 560 mg
  C) 219 mg
  D) 405 mg
  E) 337 mg

Question 2

The vapor pressure of pure ethanol at 60 C is 0.459 atm. Raoult's Law predicts that a solution prepared by dissolving 10.0 mmol naphthalene (nonvolatile) in 90.0 mmol ethanol will have a vapor pressure of ________ atm.
 
  A) 0.498
  B) 0.413
  C) 0.790
  D) 0.367
  E) 0.0918

[JaynaD87]

Answer to Question 1

A

Answer to Question 2

B

[WWatsford]

Excellent

[mohan]

Gracias!