Answer:
When 
and 
Explanation:
The spontaneity of a reaction can be determined by the sign of the Gibbs free energy change. For a spontaneous reaction, the change in Gibbs free energy should be negative, meaning:
Since the temperature value here corresponds to the absolute temperature, this implies that T > 0 for any T. Therefore, to have a negative difference for any temperature value, the first term, the change in enthalpy, should be negative and the change in entropy should be positive, so that we always subtract a positive number from a negative number. This corresponds to a negative value in 
.
Answer:
Because in elastic collisions there is no heat emission or absorption.
Explanation:
A collision is considered elastic when the total kinetic energy of the study system is conserved during the collision. Since the total kinetic energy is conserved, heat is not emitted or absorbed during the collision. Since the emission or absorption of heat is what produces changes in temperature, If the system remains at a constant temperature, there were only elastic collisions.
<h2>
Answer:</h2>
We will use dimensional analysis to solve this.
We will need the molar mass of barium, which is 137.33 g/mol.
50g × 
= .36 mol Ba
There are <em>.36 moles of barium</em> in 50g of barium
