Answer is (3) - Pb²⁺.
<em>Explanation;</em>
Among the given choices PbCl₂ is insoluble in water. But it can be soluble in hot water. It appears as white precipitate. The Ksp of PbCl₂ is very small. That's why it is insoluble in water.
Fe²⁺ + 2Cl⁻ → FeCl₂ (soluble in water. Forms pale green color solution)
Mg²⁺ + 2Cl⁻ → MgCl₂ (soluble in water. Forms clear colorless solution)
Pb²⁺ + 2Cl⁻ → PbCl₂ (poorly soluble in water. Forms white precipitation)
Zn²⁺ + 2Cl⁻ → ZnCl₂ (soluble in water. Forms clear colorless solution)
Answer: W
Explanation:
The cell in liquid W will look the smallest out of the four because of Osmosis.
Osmosis is a process by which water molecules move from an area of relatively higher concentration of water to an area with a relatively lower concentration through a selectively permeable membrane(cell membrane).
With W being saltier than the cell, water molecules will move from the cell to liquid W to balance the concentrations inside and outside the cell which will lead to the cell in W being smaller.
Answer:
The process will be spontaneous above 702 K.
Explanation:
Step 1: Given data
- Standard enthalpy of the reaction (ΔH°): 308 kJ/mol
- Standard entropy of the reaction (ΔS°): 439 J/mol.K
Step 2: Calculate the temperature range in which the process will be spontaneous
The reaction will be spontaneous when the standard Gibbs free energy (ΔG°) is negative. We can calculate ΔG° using the following expression.
ΔG° = ΔH° - T × ΔS°
When ΔG° < 0,
ΔH° - T × ΔS° < 0
ΔH° < T × ΔS°
T > ΔH°/ΔS°
T > (308,000 J/mol)/(439 J/mol.K)
T > 702 K
The process will be spontaneous above 702 K.