Determine the oxidation number for nitrogenin
each of the following
a. no2 1-
b. n2
c. no2cl
d. n2h4
2. benzene is a common hydrocarbon, whic his widely used as a
solvent.
from another experiment, the molecular mass of benzene
wasdetermined to be 78.0 grams per mole. what is the
molecularformular for benzene?

1(a) N = 3

(b) N = 0

(c) N = 5

(d) N = -2

(2) Molecular formula for benzene is C6H6

Explanation:

1(a) N02 1-

N + (2×-2) = -1

N-4 = -1

N = -1+4 = 3

(b) N2

2(N) = 0

N = 0/2 = 0

(c) NO2Cl

N + ( 2×-2) + (-1) = 0

N - 4 - 1 = 0

N - 5 = 0

N = 0+5 = 5

(d) N2H4

2(N) + (4×1) = 0

2N + 4 = 0

2N = 0 - 4 = -4

N = -4/2 = -2

(2) Molcular mass of benzene = 78g/mole = (6×12g of carbon) + (6×1g of hydrogen) = 72+6 = 78g/mole

Therefore, molecular formula for benzene is C6H6

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.