Answer:
145 grams of a 0.480 % KCN solution contains 697 mg of KCN.
Explanation:
w/w % : The percentage mass or fraction is mass of the of solute present in 100 grams of the solution.
given = w/w% = 0.480 %
Mass of solute that KCN = 697 mg = 0.697 g
(1 mg = 0.001 g)
Mass of the solution = ? = x
x = 145.21 g ≈ 145 g
145 grams of a 0.480 % KCN solution contains 697 mg of KCN.
Answer:
Is the fixed number of water molecules present in one formula unit of a substance
Explanation:
When copper sulphate is heated in a china dish, the blue colomed crystal changes to a white powder due to the removal of molecules of water of crystallization
Answer:
I would say you are correct.
Explanation:
Answer:
<em>- 0.0413°C ≅ - 0.041°C (nearest thousands).</em>
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 unsaturated zone is the portion of the subsurface above the groundwater table. The soil and rock in this zone contains air as well as water in its pores. ... Unlike the aquifers of the saturated zone below, the unsaturated zone is not a source of readily available water for human consumption
