Caffeine, the active ingredient in coffee, is composed of eight ...

[brutforce]

Caffeine, the active ingredient in coffee, is composed of eight atoms of carbon, ten atoms of hydrogen, and four atoms of nitrogen. The chemical formula of caffeine is written
 
  A) CHNO
  B) C8H10N4O2
  C) C8H10N4
  D) C8H12N4O4
  E) C8H10N4O

Question 2

A 0.600 g sample containing Ag2O and inert material is heated, causing the silver oxide to decompose according to the following equation:
 
  2 Ag2O(s)  4 Ag(s) + O2(g)
 
  If 13.8 mL of gas are collected over water at 27C and 1.00 atm external pressure, what is the percentage of silver oxide in the sample? The partial pressure of water is 26.7 mm Hg at 27C.
  A) 10.4
  B) 20.9
  C) 41.8
  D) 44.8

Question 3

Which are isoelectronic?
 
  A) Na+, Mg2+, F-
  B) S, S-2, Ar
  C) Li, Na, K
  D) K+, Ar, Cl

Question 4

Amphetamine, a commonly abused drug, is composed of nine atoms of carbon, 13 atoms of hydrogen, and one atom of nitrogen. The chemical formula of amphetamine is written
 
  A) C9H13N1
  B) C9H13
  C) C9H13N
  D) C13H93N0
  E) C9H1N13

[kaykay69]

Answer to Question 1

B

Answer to Question 2

C

Answer to Question 3

A

Answer to Question 4

C

[brutforce]

Wow, this really help

[dreamfighter72]

Gracias!