21Explanation:BEACUSE I CAN
<span>The density of the solution =1.05 g/ml.
</span><span>The total mass of the resulting solution is = 398.7 g (CaCl2 + water)
</span>
Find moles of CaCl2 and water.
Molar mass of CaCl2 = 110 (approx.)
Moles of CaCl2 = 23.7 / 110 = 0.22
so, moles of Cl- ion = 2 x 0.22 = 0.44 (because each molecule of CaCl2 will give two Cl- ions)
Moles of water = 375 / 18 = 20.83
Now, Mole fraction of CaCl2 = (moles of CaCl2) / (total moles)
total moles = moles of Cl- ions + moles of Ca2+ ions + moles of water
= 0.44 + 0.22 + 20.83
=21.49
So, mole fraction = 0.44 / (21.49) = 0.02
Guess what !!! density is not used. No need
Answer:
B.0.2 J/g°C
Explanation:
From the attached picture;
- Heat attained in the solid phase is 200 Joules
- Change in temperature is 50°C ( from 0°C to 50°C)
- Mass of the solid is 20 g
We are required to determine the specific heat capacity of the substance;
- We need to know that Quantity of heat is given by the product of mass,specific heat capacity and change in temperature.
- That is; Q = mcΔT
Rearranging the formula;
c = Q ÷ mΔT
Therefore;
Specific heat = 200 J ÷ (20 g × 50°c)
= 0.2 J/g°C
Thus, the specific heat of the solid is 0.2 J/g°C
Answer:
0.23 V.
Explanation:
<em>∵ ΔG° = -RT lnK.</em>
∴ ΔG° = -RTlnK = -(8.314 J/mol)(298 K) ln(7.3 × 10⁷) = - 44.86 x 10³ J/mol.
<em>∵ ΔG° = - nFE°</em>
∴ E° = - ΔG°/nF = - (- 44.86 x 10³ J/mol)/(2 x 96500 s.A/mol) = 0.2324 V ≅ 0.23 V.
