Nitrogen dioxide, NO2(g) (Delta. Hf = 33.84 kJ/mol), is decomposed according to the following reaction:

2 upper N upper O subscript 2 (g) right arrow upper N subscript 2 (g) plus 2 upper O subscript 2 (g).

What is the enthalpy change when 2.50 mol of nitrogen dioxide decomposes?
Use Delta H r x n equals the sum of delta H f of all the products minus the sum of delta H f of all the reactants..

13.5 kJ of energy released
13.5 kJ of energy absorbed
84.6 kJ of energy released
84.6 kJ of energy absorbed

C

Explanation:

84.6 kJ of energy released when 2.50 moles of nitrogen dioxide is decomposed.

in chemistry, a solution’s concentration is how much of a dissolvable substance, known as a solute, is mixed with another substance, called the solvent. the standard formula is c = m/v, where c is the concentration, m is the mass of the solute dissolved, and v is the total volume

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g