Answer:
Mass of KCL = 218 grams.
Explanation:
Step 1: calculate the heat that must be absorbed(q).
Heat that must be absorbed(q) is calculated as follows:
q= m c (T2-T1).
q = 750g (4.18 J/gC)(20-4 C) = 5.016X10^4 J = 50.16 kJ
Step 2: we determine moles of KCL as follows:
Moles KCl = 50.16 kJ / 17.2 kJ/mol = 2.92 moles.
Step 3: calculate mass of KCL:
Mass of KCl = 2.92 mol X 74.55 g/mol = 218g.
Therefore, 218 grams of KCL would have to be dissolved into 750 g of 20.0°C H2O to produce the solution.
Answer: form hydrogen bonds to the polar water molecules.
Explanation:
Answer is: V<span>an't Hoff factor (i) for this solution is 2,26.
</span>Change in freezing point
from pure solvent to solution: ΔT =i · Kf · m.
<span>Kf - molal freezing-point depression constant for water is 1,86°C/m.
</span>m - molality, moles of solute per kilogram of solvent.
n(K₂SO₄) = 16,8 g ÷ 174,25 g/mol
n(K₂SO₄) = 0,096 mol.
m(K₂SO₄) = 0,096 mol/kg.
ΔT = 0,405°C.
i = 0,405 ÷ (1,86 · 0,096)
i = 2,26.
Answer:
Ionic compounds: They have high melting points and boiling points. That is, ionic compounds are non-volatile.
Covalent compounds: They have usually low melting points and boiling points. That is, covalent compounds are usually volatile.
Answer:
BaF2(s) ------> Ba2 (aq) + 2F- (aq)
Explanation:
Entropy refers to the degree of disorderliness in a system. Processes that lead to greater disorderliness in a system are said to increase the entropy of the system or lead to a positive value of ΔS.
If we consider the process, BaF2(s) ------> Ba2 (aq) + 2F- (aq), we will notice that ions were produced in solution thereby increasing the disorderliness of the system.
