Chose the correct acidity orders among the following.
(1) `H_(3)AsO_(4) < H_(3)PO_(4)`
(2) `H_(2)CO_(3) >H_(3)BO_(3)`
(3) `H_(3)AsO_(4)< H_(3)AsO_(2)`

Options

A. 1 and3
B. 1 and 2
C. 3 only
D. 2 and 3

Answer

To determine the correct acidity orders among the given oxyacids, we will analyze each pair based on the oxidation states of their central atoms and their sizes.

### Step 1: Analyze the first pair - `H3AsO4 < H3PO4`
- **Oxidation States**:
- In `H3AsO4`, arsenic (As) has an oxidation state of +5.
- In `H3PO4`, phosphorus (P) also has an oxidation state of +5.
- **Size Comparison**:
- Arsenic is larger than phosphorus.
- **Conclusion**: Since both have the same oxidation state but arsenic is larger, `H3AsO4` is less acidic than `H3PO4`. Thus, this statement is correct.

### Step 2: Analyze the second pair - `H2CO3 > H3BO3`
- **Oxidation States**:
- In `H2CO3`, carbon (C) has an oxidation state of +4.
- In `H3BO3`, boron (B) has an oxidation state of +3.
- **Conclusion**: Since carbon has a higher oxidation state than boron, `H2CO3` is more acidic than `H3BO3`. Thus, this statement is correct.

### Step 3: Analyze the third pair - `H3AsO4 < H3AsO2`
- **Oxidation States**:
- In `H3AsO4`, arsenic (As) has an oxidation state of +5.
- In `H3AsO2`, arsenic has an oxidation state of +3.
- **Conclusion**: Since `H3AsO4` has a higher oxidation state than `H3AsO2`, it should be more acidic. Therefore, this statement is incorrect.

### Final Conclusion:
- The correct acidity orders are:
- (1) `H3AsO4 < H3PO4` is correct.
- (2) `H2CO3 > H3BO3` is correct.
- (3) `H3AsO4 < H3AsO2` is incorrect.

Thus, the correct options are (1) and (2).