Some statements are given with regard to entropy. The incorrect statement(s) are
(A) The absolute entropy of substances cannot be determined
(B) In standard state entropy of elements is always positive
(C ) The entropy of universe always decreases
(D) In a spontaneous process, for an isolated system the entropy of the system generally increases

Options

A. A,B
B. B,C
C. A,C
D. Only C

Answer

To solve the question regarding the statements about entropy, we will analyze each statement one by one to determine which ones are incorrect.

### Step-by-Step Solution:

1. **Statement A: The absolute entropy of substances cannot be determined.**
- This statement is **incorrect**. According to the Third Law of Thermodynamics, the absolute entropy of a perfect crystalline substance at absolute zero temperature is defined to be zero. This provides a reference point from which the absolute entropy of other substances can be calculated. Therefore, the absolute entropy of substances can indeed be determined.

2. **Statement B: In standard state, the entropy of elements is always positive.**
- This statement is **correct**. The standard state entropy of elements is always positive because it reflects the degree of disorder or randomness in the system. Even in their most stable form, elements possess some degree of entropy due to their molecular motion.

3. **Statement C: The entropy of the universe always decreases.**
- This statement is **incorrect**. The Second Law of Thermodynamics states that the total entropy of an isolated system, such as the universe, can never decrease over time; it either increases or remains constant. Thus, the entropy of the universe is always increasing.

4. **Statement D: In a spontaneous process, for an isolated system, the entropy of the system generally increases.**
- This statement is **correct**. In spontaneous processes, the entropy of an isolated system tends to increase, reflecting the natural tendency for systems to evolve towards a state of greater disorder.

### Conclusion:
The incorrect statements are **A** and **C**.

### Final Answer:
The incorrect statements are **A and C**.

---