Answer:
A. Soaps react with ions in hard water to create a precipitate.
B. Soaps are both hydrophobic and hydrophilic.
D. Soaps should be weakly alkaline in solution.
Explanation:
A. Hard water contains <u>magnesium and calcium minerals</u> like calcium and magnesium carbonates, sulfates and bicarbonates. As soon as these minerals come in contact with soap their ions like Mg²⁺ & Ca²⁺ form precipitates.
B. Soap are both hydrophilic and hydrophobic. They reason why they exhibit both the properties is really important for their functionality. The hydrophobic part of soap makes interaction with oil/dust particles while the hydrophilic part makes interaction with water. When the cloth is rinsed the dirt/soap particles are removed from the dirty clothes thereby making them clean.
C. Soaps have alkaline pH i.e. more than 7 that is why they have bitter taste.
Answer:
a) +640 kJ/mol or +1.06x10⁻¹⁸ J
b) +276 kJ/mol
Explanation:
To dissociate the molecule, the bond must be broken, thus, it's necessary energy equal to the energy of the bond, which can be calculated by:
E = (Q1*Q2)/(4*π*ε*r)
Where Q is the charge of the ions, ε is a constant (8.854x10⁻¹²C²J ⁻¹ m⁻¹), and r is the bond length. Each one of the ions has a charge equal to 1. The elementary charge is 1.602x10⁻¹⁹C, which will be the charge of them.
1 mol has 6.022x10²³ molecules (Avogadros' number), so the energy of 1 mol is the energy of 1 molecule multiplied by it:
E = 6.022x10²³ *(1.602x10⁻¹⁹)²/(4π*8.854x10⁻¹²*2.17x10⁻¹⁰)
E = +640113 J/mol
E = +640 kJ/mol
Or at 1 molecule: E =640/6.022x10²³ = +1.06x10⁻²¹ kJ = +1.06x10⁻¹⁸ J
b) The energy variation to dissociate the molecule at its neutral atoms is the energy of dissociation less the difference of the ionization energy of K and the electron affinity of F (EA):
498 = 640 - (418 - EA)
640 -418 + EA = 498
222 + EA = 498
EA = +276 kJ/mol
A structural formula for an organic compound that depicts each valence bond as a short line especially : the hexagonal ring formula for benzene
A eukaryotic cell goes through nuclear division creating two identical daughter cells.
I believe this would be a chemical compound, yet it is not one of the options present.
