Which of the following contains same number of carbon atoms as are in 6.0 g of carbon (C – 12)?
A
6.0 g Ethane
B
8.0 g Methane
C
21.0 g Propane
D
28.0 g CO
Answer:
The correct option is B. 8.0 g Methane
Note
6g carbon
Moles of carbon = (6/12) = 0.5 mol
Number of carbon atoms
= 0.5 × NA =0.5NA (NA is Avogadro number)
6g ethane (C2H6 two atoms of C per mole)
Moles = (6/30) = 0.2 mol
Number of carbon atoms = 0.2 × 2 × NA = 0.4 NA
(Number of carbon atoms = moles of compound × number of C atoms per mol × Avogadro number)
8g methane (CH4)
Moles = (8/16) = 0.5 mol
Number of carbon atoms = 0.5 × 1 × NA = 0.5 NA
21g propane (C3H8)
Moles = (21/44) =0.48 mol
Number of carbon atoms = 0.48 × 3 × NA = 1.44 NA
28g CO
Moles = (28/28) =1 mol
Number of carbon atoms = 1 × 1 × NA = NA