Answer:
The correct answer is B. It is spontaneous only at low temperatures.
Explanation:
In thermodynamics, the Gibbs free energy is a thermodynamic potential that can be used to calculate the maximum of reversible work that may be performed by a thermodynamic system at a constant temperature and pressure.
The spontaneity of a reaction is given by the equation:
ΔG = ΔH - TΔS
where:
ΔH: enthalpy variation
T: absolute temperature
ΔS: entropy variation
As the reaction is exothermic, ΔH<0
As the reaction order increases (the reagents are solid and gas and their product is solid), ΔS<0
Therefore, the reaction will be spontaneous when ΔG is negative.
ΔG = ΔH - TΔS
That is, the entropy term must be smaller than the enthalpy term.
Hence, the reaction will be spontaneous only at low temperatures.
Answer:
She can add 380 g of salt to 1 L of hot water (75 °C) and stir until all the salt dissolves. Then, she can carefully cool the solution to room temperature.
Explanation:
A supersaturated solution contains more salt than it can normally hold at a given temperature.
A saturated solution at 25 °C contains 360 g of salt per litre, and water at 70 °C can hold more salt.
Yasmin can dissolve 380 g of salt in 1 L of water at 70 °C. Then she can carefully cool the solution to 25 °C, and she will have a supersaturated solution.
B and D are wrong. The most salt that will dissolve at 25 °C is 360 g. She will have a saturated solution.
C is wrong. Only 356 g of salt will dissolve at 5 °C, so that's what Yasmin will have in her solution at 25 °C. She will have a dilute solution.
Answer:
Gold
Explanation:
Gold(I) chloride is a compound of gold and chlorine with the chemical formula AuCl
Answer:
K = 3.37
Explanation:
2 NH₃(g) → N₂(g) + 3H₂(g)
Initially we have 4 mol of ammonia, and in equilibrium we have 2 moles, so we have to think, that 2 moles have been reacted (4-2).
2 NH₃(g) → N₂(g) + 3H₂(g)
Initally 4moles - -
React 2moles 2m + 3m
Eq 2 moles 2m 3m
We had produced 2 moles of nitrogen and 3 mol of H₂ (ratio is 2:3)
The expression for K is: ( [H₂]³ . [N₂] ) / [NH₃]²
We have to divide the concentration /2L, cause we need MOLARITY to calculate K (mol/L)
K = ( (2m/2L) . (3m/2L)³ ) / (2m/2L)²
K = 27/8 / 1 → 3.37
Answer:
Molecular weight of the compound = 372.13 g/mol
Explanation:
Depression in freezing point is related with molality of the solution as:
Where,
= Depression in freezing point
= Molal depression constant
m = Molality
m = 0.26
Molality = 
Mass of solvent (toluene) = 15.0 g = 0.015 kg
Moles of compound = 0.015 × 0.26 = 0.00389 mol
Mass of the compound = 1.450 g
Molecular weight = 
