Review Questions

1 . What    is  the sum of  the coefficients    of  the following   equation    when    it  is  balanced?

C 6 H 12 O 6 + O 2 → CO 2 + H 2 O

(A) 20

(B) 38

(C) 21

(D) 19

(E) 18

2 . Determine   the molecular   formula and calculate   the percent composition of  each    element

present in  nicotine,   which   has an  empirical   formula of  C 5 H 7 N   and a   molecular   weight  of

162 g/mol.

3 . Acetylene,  used    as  a   fuel    in  welding torches,    is  produced    in  a   reaction    between calcium

carbide and water:

CaC 2   +   2H 2 O  →   Ca(OH) 2    +   C 2 H 2

How many    grams   of  C 2 H 2     are formed  from    0.400   moles   of  CaC 2?

(A) 0.400

(B) 0.800

(C) 4.00

(D) 10.4

(E) 26.0