Which of the following statements are correct ?

Options

A. According to Bronsted Lowry concept, `H_(2)SO_(4)` can also act as a base
B. `SiF_(4)` is an acid according to Lewis concept
C. Stronger the acid, higher is its `pK_(a)` value
D. HCl, `HNO_(3) and H_(2)SO_(4)` act as equally strong acids in any solvent.

Explanation

To determine which statements are correct, we will analyze each statement one by one based on the concepts of acid-base chemistry, specifically the Bronsted-Lowry and Lewis definitions.

### Step-by-Step Solution:

1. **Statement Analysis:**
- **Statement 1:** "According to Bronsted-Lowry concept, H2SO4 can also act as a base."
- **Analysis:** According to the Bronsted-Lowry theory, an acid is a proton donor and a base is a proton acceptor. H2SO4 is primarily known as a strong acid, but it can accept protons in certain reactions, thus acting as a base. This statement is **correct**.

2. **Statement Analysis:**
- **Statement 2:** "SiF4 is an acid according to Lewis concept."
- **Analysis:** The Lewis definition states that an acid is an electron pair acceptor. SiF4 can accept electron pairs due to the presence of an empty p-orbital on silicon. Therefore, SiF4 can be classified as a Lewis acid. This statement is **correct**.

3. **Statement Analysis:**
- **Statement 3:** "Stronger the acid, higher is its pKa value."
- **Analysis:** The pKa value is inversely related to the strength of an acid. A stronger acid has a lower pKa value. Therefore, this statement is **incorrect**.

4. **Statement Analysis:**
- **Statement 4:** "HCl, HNO3, and H2SO4 act as equally strong acids in any solvent."
- **Analysis:** While HCl, HNO3, and H2SO4 are strong acids in water, their strength can vary in different solvents. For example, in non-aqueous solvents, their acid strengths may differ. Thus, this statement is **incorrect**.

### Conclusion:
From the analysis above, we conclude that:
- Statement 1 is correct.
- Statement 2 is correct.
- Statement 3 is incorrect.
- Statement 4 is incorrect.

Therefore, the correct answers are **A and B**.