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: 1.80g
Explanation:
Molar Mass of AlCl3 = 27 + (3x35.5)
= 27 + 106.5 = 133.5g/mol
Number of mole of AlCl3 = 0.0135mol
Mass = 0.0135 x 133.5= 1.80g
Answer:
The answer is
<h2>0.075 kg</h2>
Explanation:
The mass of a substance when given the density and volume can be found by using the formula
<h3>mass = Density × volume</h3>
From the question
density = 762 kg/m³
We must first convert the volume from cm³ to m³
So 99 cm³ will be
So the mass of the material is
We have the final answer as
<h3>0.075 kg</h3>
Hope this helps you
