Answer:
The answer is: (a) positive; (b) negative.
Explanation:
The change in enthalpy (ΔH) of a reaction is the amount of energy absorbed or released during a chemical reaction carried out at constant pressure.
a) In an endothermic chemical reaction, heat energy is absorbed by the system from the surrounding. Therefore, the sign of enthalpy change for an endothermic process is positive, ΔH= positive.
b) In an exothermic chemical reaction, heat energy is released by the system into the surrounding. Therefore, the sign of enthalpy change for an exothermic process is negative, ΔH= negative.
Answer:
From what i've learned so far, the correct answer is "Heat at a constant Pressure" or "Specific Heat"
Explanation:
Hope this helps!
Answer:
The correct answer is D
Explanation:
Many substances hold their molecules together in the liquid or solid bosom. This is due, in addition to the pressure and temperature conditions, by the forces of Van der Waals. These are still produced in nonpolar molecules by the movement of electrons through the molecules; in extremely short periods of time, their electrons "charge" towards one end of the molecule, producing small dipoles and keeping the molecules very close to each other.
The large piece of jewelry that has a mass of 132.6 g and when is submerged in a graduated cylinder that initially contains 48.6 ml water and the volume increases to 61.2 ml once the piece of jewelry is submerged, has a density of: 10.523 g/ml
To solve this problem the formulas and the procedures that we have to use are:
Where:
- d= density
- m= mass
- v= volume
- v(f) = final volume
- v(i) = initial volume
Information about the problem:
- m = 132.6 g
- v(i) = 48.6 ml
- v(f) = 61.2 ml
- v = ?
- d =?
Applying the volume formula we get:
v = v(f)-v(i)
v = 61.2 ml - 48.6 ml
v = 12.6 ml
Applying the density formula we get:
d = m/v
d = 132.6 g/12.6 ml
d = 10.523 g/ml
<h3>What is density?</h3>
It is a physical quantity that expresses the ratio of the body mass to the volume it occupies.
Learn more about density in: brainly.com/question/1354972
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