Answer:
2 atm
Explanation:
Chemical reactions are carried out at a certain rate. Sometimes that rate is quite slow, so we want to speed things up, which is usually used by increasing temperature, increasing pressure or adding a catalyst (a substance that increases the rate without changing itself).
If this is the case, then, when writing a chemical equation, we state these special conditions over a right arrow.
Now let's look at the answers:
- 25°C is a value and unit of temperature
- ∆ is a symbol that denotes change
- 2 atm is a value and unit of pressure (atmosphere is old unit for pressure)
- Pt is a chemical symbol for platinum, an element often used as a catalyst.
So, the correct answer is C) 2 atm
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
.
The answer to this question is Contact
depending on the geological event that put into place, this will have a specific semantic value.
A contact usually represented by different kind of lines on the geological map and usually use to determine <span>where rocks come into contact across fault zones</span>