Answer is: adding NaCl will lower the freezing point of a solution.
A solution (in this example solution of sodium chloride) freezes at a lower temperature than does the pure solvent (deionized water).
The higher the solute concentration (sodium chloride), freezing point depression of the solution will be greater.
Equation describing the change in freezing point:
ΔT = Kf · b · i.
ΔT - temperature change from pure solvent to solution.
Kf - the molal freezing point depression constant.
b - molality (moles of solute per kilogram of solvent).
i - Van’t Hoff Factor.
Dissociation of sodium chloride in water: NaCl(aq) → Na⁺(aq) + Cl⁻(aq).
Answer:
0.0084
Explanation:
The mole fraction of BaCl₂ (X) is calculated as follows:
X = moles BaCl₂/total moles of solution
Given:
moles of BaCl₂ = 0.400 moles
mass of water = 850.0 g
We have to convert the mass of water to moles, by using the molecular weight of water (Mw):
Mw of water (H₂O) = (2 x 1 g/mol)+ 16 g/mol = 18 g/mol
moles of water = mass of water/Mw of water = 850.0 g/(18 g/mol) = 47.2 mol
The total moles of the solution is given by the addition of the moles of solute (BaCl₂) and the moles of solvent (water):
total moles of solution = moles of BaCl₂ + moles of water = 0.400 + 47.2 mol = 47.6 mol
Finally, we calculate the mole fraction:
X = 0.400 mol/47.6 mol = 0.0084
Answer:
The answer is IONIC BOND
Explanation:
Steroidogenic acute regulatory, (StAR) protein is a type of globular protein, which allows it act as an active catalyst on substrates. Because the substrates on which enzymes act usually have higher molecular weights of several hundred as compared to the enzymes, only a fraction of the enzyme's surface is in contact with the substrate. This region of contact called the <em>active site</em>, is as a result of the protein folding itself into a tertiary structure.
Once the correct substrate has bound at the active site of the enzyme, an enzyme-substrate complex is created. The substrate is usually held in the complex by combinations of electrical attraction, hydrophobic repulsion, or hydrogen bonding between and from the amino acid; the strongest of which is the ionic/electrostatic bonding due to larger amount of ionic "R" groups in the protein structure.
So whilst all these inter-molecular interactions are possible, the strongest would be <u>ionic bond.</u>
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