Answer:
NiS insoluble
Mg₃(PO₄)₂ insoluble
Li₂CO₃ soluble
NH₄Cl soluble
C₁₂H₂₂O₁₁ molecules
Explanation:
<em>Predict whether the following compounds are soluble or insoluble in water.</em>
Based on the solubility rules we can say:
- NiS: Sulfides of transition metals are highly insoluble.
- Mg₃(PO₄)₂: All phosphates (except those with metals of Group 1) are insoluble so Mg₃(PO₄)₂ is insoluble.
- Li₂CO₃: all salts of metals of Group 1 are soluble so Li₂CO₃ is soluble.
- NH₄Cl: all salts of ammonium are soluble so NH₄Cl is soluble.
<em>Which of the following best describes the solute in an aqueous solution of sucrose or C₁₂H₂₂O₁₁(aq)?</em>
Sucrose is a molecular compound in which atoms are linked through covalent bonds. Thus, it does not ionize in water (is a non-electrolyte) and when it dissolves it exists as C₁₂H₂₂O₁₁ molecules.
The solution that will have the lowest freezing point is 5.0 SODIUM CHLORIDE.
Adding solute to solvents usually result in the depression of the freezing point. The higher the quantity of the solute that is added, the lower the freezing point of the solution.
Answer: -112200J
Explanation:
The amount of heat (Q) released from an heated substance depends on its Mass (M), specific heat capacity (C) and change in temperature (Φ)
Thus, Q = MCΦ
Since,
Q = ?
Mass of water vapour = 30.0g
C = 187 J/ G°C
Φ = (Final temperature - Initial temperature)
= 100°C - 120°C = -20°C
Then apply the formula, Q = MCΦ
Q = 30.0g x 187 J/ G°C x -20°C
Q = -112200J (The negative sign does indicates that heat was released to the surroundings)
Thus, -112200 joules of heat is released when cooling the superheated vapour.
