Which of the following statements is true?

Options

A. `NaHCO_(3)` is strongly basic in nature
B. Pure NaCl is hygroscopic
C. On increasing temperature increase in solubility of NaCl in water occurs
D. All of these

Answer

To determine which statement is true among the given options, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Analyze Option 1: Na2CO3 is strongly basic in nature.**
- Sodium carbonate (Na2CO3) is a salt derived from a strong base (NaOH) and a weak acid (H2CO3). It can hydrolyze in water to produce hydroxide ions (OH⁻), which makes it basic. However, it is not considered "strongly basic" like NaOH. Therefore, this statement is **incorrect**.

2. **Analyze Option 2: Pure NaCl is hygroscopic.**
- Hygroscopic substances are those that can absorb moisture from the air. Pure sodium chloride (NaCl) does not absorb moisture from the air under normal conditions; it remains dry. Therefore, this statement is also **incorrect**.

3. **Analyze Option 3: On increasing temperature, the solubility of NaCl in water occurs.**
- Sodium chloride (NaCl) is an ionic compound, and typically, the solubility of ionic solids in water increases with an increase in temperature. This is a well-known principle in chemistry. Therefore, this statement is **correct**.

4. **Analyze Option 4: All of these.**
- Since we have determined that options 1 and 2 are incorrect, option 4, which states "all of these," is also **incorrect**.

### Conclusion:
After analyzing all the options, we find that the only true statement is **Option 3: On increasing temperature, the solubility of NaCl in water occurs.**

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