It will be a. <span>benzene.</span>
Answer:
The temperature should be higher than 437.9 Kelvin (or 164.75 °C) to be spontaneous
Explanation:
<u>Step 1:</u> Data given
ΔH∘=20.1 kJ/mol
ΔS is 45.9 J/K
<u>Step 2:</u> When is the reaction spontaneous
Consider temperature and pressure = constant.
The conditions for spontaneous reactions are:
ΔH <0
ΔS > 0
ΔG <0 The reaction is spontaneous at all temperatures
ΔH <0
ΔS <0
ΔG <0 The reaction is spontaneous at low temperatures ( ΔH - T*ΔS <0)
ΔH >0
ΔS >0
ΔG <0 The reaction is spontaneous at high temperatures ( ΔH - T*ΔS <0)
<u>Step 3:</u> Calculate the temperature
ΔG <0 = ΔH - T*ΔS
T*ΔS > ΔH
T > ΔH/ΔS
In this situation:
T > (20100 J)/(45.9 J/K)
T > 437.9 K
T > 164.75 °C
The temperature should be higher than 437.9 Kelvin (or 164.75 °C) to be spontaneous
The mole fraction of solute in a 3.87 m aqueous solution is 0.0697
<h3>
calculation</h3>
molality = moles of the solute/Kg of the solvent
3.87 m dissolve in 1 Kg of water= 1000g
find the moles of water= mass/molar mass
that is 1000 g/ 18 g/mol= 55.56 moles
mole of solute = 3.87 moles
mole fraction is = moles of solute/moles of solvent
that is 3.87/ 55.56 = 0.0697
If you have an aqueous solution that contains 1.5 moles of HCl, the number of moles of ions in the solution is 3.0 moles.
<h2>Further Explanation
</h2><h3>Strong acids </h3>
- Strong acids are types of acids that undergo complete dissociation to form ions when dissolved in water.
- Examples of such acids are, HCl, H2SO4 and HNO3
- Dissociation of HCl
HCl + H₂O ⇔ H₃O⁺ + OH⁻
<h3>Weak acids </h3>
- Weak acids are types of acids that undergo incomplete dissociation to form ions when dissolved in water.
- Examples of such acids are acetic acids and formic acids.
- Dissociation of acetic acid
H₃COOH ⇔ CH₃COO⁻ + H⁺; CH₃COO⁻ is a conjugate base of acetic acid.
<h3>In this case;</h3>
- HCl which is a strong acid that ionizes completely according to the equation;
HCl + H₂O ⇔ H₃O⁺ + OH⁻
- From the equation, 1 mole of HCl produces 1 mole of H₃O⁺ ions and 1 mole of OH⁻ ions.
Therefore;
1.5 moles of HCl will produce;
= 1.5 moles of H₃O⁺ ions and 1.5 moles of OH⁻ ions.
This gives a total number ions of;
= 1.5 + 1.5
= 3 moles of ions
Keywords: Strong acid, weak acid, ions, ionization
<h3>Learn more about: </h3>
Level: High school
Subject: Chemistry
Topic: Salts, Acids and Bases
