As long as the equation in question can be expressed as the sum of the three equations with known enthalpy change, its 
can be determined with the Hess's Law. The key is to find the appropriate coefficient for each of the given equations.
Let the three equations with given be denoted as (1), (2), (3), and the last equation (4). Let 
, 
, and 
be letters such that 
. This relationship shall hold for all chemicals involved.
There are three unknowns; it would thus take at least three equations to find their values. Species present on both sides of the equation would cancel out. Thus, let coefficients on the reactant side be positive and those on the product side be negative, such that duplicates would cancel out arithmetically. For instance, 
shall resemble the number of 
left on the product side when the second equation is directly added to the third. Similarly
Thus
and
Verify this conclusion against a fourth species involved- 
for instance. Nitrogen isn't present in the net equation. The sum of its coefficient shall, therefore, be zero.
Apply the Hess's Law based on the coefficients to find the enthalpy change of the last equation.
Answer: c = 710 J/kg°C or 0.71 J/g°C
Explanation: Heat is expressed in the formula Q = mc∆T. Derive to find the specific heat c. So the formula will become c = Q / m∆T
c = Q / m∆T
= 42600 J / 2 kg ( 55°C - 25°C )
= 710 J /kg°C
Or can be expressed by converting kg to g.
c = 0.71 J /g°C
Answer:
Temperature decreases and density increases
Explanation:
Let us remember that density of a material increases as the temperature of the material decreases. So the cooler a material becomes, the denser it becomes also.
Between points B and C, the material rapidly cools down and the temperature decreases accordingly. This ultimately results in an increase in density since cooler materials are denser than hot materials.
The job outlook for physical therapists<u> "will improve over time".</u>
Physical therapists, help harmed or sick individuals enhance their development and deal with their agony. These therapists are frequently an imperative piece of the restoration, treatment, and counteractive action of patients with unending conditions, ailments, or wounds.
Physical therapists commonly work in private workplaces and centers, clinics, patients' homes, and nursing homes. They invest quite a bit of their energy in their feet, effectively working with patients.
:
:
:
