5) answer is A 2NaHCO3(s) + 129k) - Na2CO3(s) + H2(g) + CO2(g)
This equation indicates that AH is
and energy must be
to complete the reaction.
A)
positive; added
B)
negative; added
C)
positive; released
D)
negative; released

A)  positive; added

Explanation:

Based on the reaction:

2NaHCO3(s) + 129kJ → Na2CO3(s) + H2(g) + CO2(g)

2 moles of NaHCO3 requires 129kJ to produce 1 mole of Na2CO3, 1 mole of H2 and 1 mole of CO2.

That means, the energy must be added being, thus, an exothermic reaction. The exothermic reactions have ΔH >0.

Thus, right answer is:

A)  positive; added

h let me think

answer; i believe the correct answer is (c) /// is a homogeneous mixture of gaseous substance nitrogen,oxygen and smaller amounts of other substancesmixtures can be either ( homogeneous or heterogeneous)plz check first good luck