Answer:
- 0.99 °C ≅ - 1.0 °C.
Explanation:
- We can solve this problem using the relation:
<em>ΔTf = (Kf)(m),</em>
where, ΔTf is the depression in the freezing point.
Kf is the molal freezing point depression constant of water = -1.86 °C/m,
m is the molality of the solution (m = moles of solute / kg of solvent = (23.5 g / 180.156 g/mol)/(0.245 kg) = 0.53 m.
<em>∴ ΔTf = (Kf)(m)</em> = (-1.86 °C/m)(0.53 m) =<em> - 0.99 °C ≅ - 1.0 °C.</em>
Answer:
What I've done:
Molar mass of Zn: 65.409 g/mol
Molar mass of Cl: 2*35.453 =70.906 g/mol
Molar mass of O: 6*15.9994 =95.9964 g/mol
Total molar mass of Zn(ClO3)2: 232.3114 g/mol
21% of molar mass = 232.3114 g/mol
100% of mass = 1106.244762 g/mol
Molar mass of H2O: 18.01528 g/mol
232.3114 g/mol + 18.01528 g/mol = 250.32668 g/mol
250.32668 = 1106.244762
1106.244762 g/mol divided by 232.3114 g/mol
x = 4.419
Explanation:
% anything = (g/total mass)*100 = ?
Atomic mass Zn = 65.4 from your post.
molar mass Zn(ClO3)2 from your post = 232.3
molar mass H2O = 18
The 21.5% Zn is (note you used 21%) percent Zn in the hydrate so
%Zn = [(65.4)/(232.3 + x*18)]*100 = 21.5%
Solve for x and I obtained 3.99 which rounds to 4.00. Let me know if you don't understand any part.
Energy from a light source is known as radiation.
#48 might be (A) but in not for sure
