Answer:
13.3 %
Explanation:
Percent by mass indicates the mass of solute in 100g of solution.
We must know the solution's mass:
Solution's mass = Solute mass + solvent mass
Solution's mass = 10 g + 65 g = 75 g
Percent by mass = (10 g / 75 g).100 = 13.3 %
Otherwise, we can make a rule of three:
In 75 g of solution we have 10 g of solute
In 100 g of solution we must have (100 . 10) /75 = 13.3 %
Answer:
- 0.0413°C ≅ - 0.041°C (nearest thousands).
Explanation:
- Adding solute to water causes the depression of the freezing point.
<em>ΔTf = Kf.m,</em>
Where,
ΔTf is the change in the freezing point.
Kf is the freezing point depression constant (Kf = 1.86 °C/m).
m is the molality of the solution.
<em>Molality is the no. of moles of solute per kg of the solution.</em>
- <em>no. of moles of solute (glucose) = mass/molar mass</em> = (8.44 g)/(180.156 g/mol) = <em>0.04685 mol.</em>
<em>∴ molality (m) = no. of moles of solute/kg of solvent</em> = (0.04685 mol)/(2.11 kg) = <em>0.0222 m.</em>
∴ ΔTf = Kf.m = (1.86 °C/m)(0.0222 m) = 0.0413°C.
<em>∴ The freezing point of the solution = the freezing point of water - ΔTf </em>= 0.0°C - 0.0413°C = <em>- 0.0413°C ≅ - 0.041°C (nearest thousands).</em>
The carbon cycle is nature's way of reusing carbon atoms, which travel from the atmosphere into organisms in the Earth and then back into the atmosphere over and over again. Most carbon is stored in rocks and sediments, while the rest is stored in the ocean, atmosphere, and living organisms
4 steps of Carbon Cycle
Photosynthesis, Decomposition, Respiration and Combustion.
