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.
q = mCΔT
The correct specific heat capacity of water is <em>4.187 kJ/(kg.K)</em>.
ΔT = q/mC = 87 kJ/[648.00 kg x 4.187 kJ/(kg.K)] = 87 kJ/(2713 kJ/K) = 0.032 K
Tf = Ti + ΔT = 298 K + 0.032 K = 298.032 K
Answer:
9.63 L.
Explanation:
Hello,
In this case, the undergoing chemical reaction is:
So the consumed amounts of hydrochloric acid and bromine are the same to the beginning based on:
In such a way, the yielded moles of hydrobromic acid and chlorine are:
Thus, the volume of the sample, after the reaction is the same as no change in the total moles is evidenced, that is 9.63L.
Best regards.
The chemist the count the number of particles (Atoms, Molecules or Formula Unit) in a given number of moles of a substance by using following relationship.
Moles = # of Particles / 6.022 × 10²³
Or,
# of Particles = Moles × 6.022 × 10²³
So, from above relation it is found that 1 mole of any substance contains exactly 6.022 × 10²³ particles. Greater the number of moles greater will be the number of particles.
