Answer :
To identify which substances are likely to dissociate in water, we need to understand the general properties of these substances. Dissociation in water typically occurs for ionic compounds and strong bases.
Here are the substances given:
1. Sodium bromide (NaBr):
- This is an ionic compound, composed of sodium ions (Na⁺) and bromide ions (Br⁻). Ionic compounds generally dissociate in water as they separate into their constituent ions.
- Dissociates in water.
2. Potassium hydroxide (KOH):
- This is a strong base and also an ionic compound. It dissociates in water into potassium ions (K⁺) and hydroxide ions (OH⁻).
- Dissociates in water.
3. Magnesium chloride (MgCl₂):
- This is another ionic compound, consisting of magnesium ions (Mg²⁺) and chloride ions (Cl⁻). It dissociates into its ions easily in water.
- Dissociates in water.
4. Silicon dioxide (SiO₂):
- This is a covalent compound and does not readily dissociate in water. It is actually known for its low solubility in water.
- Does not dissociate in water.
5. Sodium oxide (Na₂O):
- This is an ionic compound as well, which dissociates in water to form sodium ions (Na⁺) and oxide ions (O²⁻). However, the oxide ions will quickly react with water to form hydroxide ions (OH⁻), making the overall process a dissociation.
- Dissociates in water.
So, the substances that are likely to dissociate in water are:
- Sodium bromide (NaBr)
- Potassium hydroxide (KOH)
- Magnesium chloride (MgCl₂)
- Sodium oxide (Na₂O)
These substances dissociate into their respective ions when dissolved in water. Only silicon dioxide (SiO₂) does not dissociate in water.
Here are the substances given:
1. Sodium bromide (NaBr):
- This is an ionic compound, composed of sodium ions (Na⁺) and bromide ions (Br⁻). Ionic compounds generally dissociate in water as they separate into their constituent ions.
- Dissociates in water.
2. Potassium hydroxide (KOH):
- This is a strong base and also an ionic compound. It dissociates in water into potassium ions (K⁺) and hydroxide ions (OH⁻).
- Dissociates in water.
3. Magnesium chloride (MgCl₂):
- This is another ionic compound, consisting of magnesium ions (Mg²⁺) and chloride ions (Cl⁻). It dissociates into its ions easily in water.
- Dissociates in water.
4. Silicon dioxide (SiO₂):
- This is a covalent compound and does not readily dissociate in water. It is actually known for its low solubility in water.
- Does not dissociate in water.
5. Sodium oxide (Na₂O):
- This is an ionic compound as well, which dissociates in water to form sodium ions (Na⁺) and oxide ions (O²⁻). However, the oxide ions will quickly react with water to form hydroxide ions (OH⁻), making the overall process a dissociation.
- Dissociates in water.
So, the substances that are likely to dissociate in water are:
- Sodium bromide (NaBr)
- Potassium hydroxide (KOH)
- Magnesium chloride (MgCl₂)
- Sodium oxide (Na₂O)
These substances dissociate into their respective ions when dissolved in water. Only silicon dioxide (SiO₂) does not dissociate in water.