To get the melting point of a solution so, we will use this formula:
ΔT = - mKf
when:
m is molality of the solution
Kf is cryoscopic constant of water = 1.86 C/m
and ΔT is the change in melting point (T2 - 0 °C)
so, now we need to calculate the molality to substitute:
when the molality = moles NaCl / Kg of water
and when moles NaCl = mass / molar mass
= 2.5 g / 58 g/mol
= 0.043 mol
∴ Kg water = volume *density /1000
= 230 mL * 1 g/mL / 1000
= 0.23 Kg
∴ molality = 0.043 / 0.23 =0.187 M
by substitution:
T2-0°C = - 0.187 * 1.86
∴T2 = - 0.348 °C
Answer:
A
Explanation:
Clear glass reflects light, but frosted glass absorbs light.
Answer:
the reducing agent is the Na ion, therefore the Na ion is oxidised. The oxidising agent is Cl ion, therefore the Cl ion is reduced.
Answer:
60 g/100 g water
Explanation:
Find 5 °C on the horizontal axis.
Draw a line vertically from that point until you reach the solubility curve for CaCl₂.
Then draw a horizontal line from there to the vertical axis.
The solubility of CaCl₂ is 60 g/100 g water.
