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:
k+
Ba2+
Al3+
K+
S2-
you may think that if it has a + it would be bigger, but it is actually the opposite.
Answer : The mass percentage of isopropyl alcohol in the solution is, 59.4 %
Explanation :
To calculate the mass percentage of isopropyl alcohol in the solution, we use the equation:
Mass of isopropyl alcohol = 6.68 g
Mass of isopropyl alcohol solution = 3.97 g
Putting values in above equation, we get:
Thus, the mass percentage of isopropyl alcohol in the solution is, 59.4 %
The correct answer to this item is letter
C. convection in earth's mantle
Convection currents move tectonic plates when the rising mantle creates heat inside. The radioactive decay of several substances is responsible for the creation of the convection currents.
