Answer:
3.74g of ethylene glycol must be added to decrease the freezing point by 0.400°C
Explanation:
One colligative property is the freezing point depression due the addition of a solute. The equation is:
ΔT=Kf*m*i
<em>Where ΔT is change in temperature = 0.400°C</em>
<em>Kf is freezing point constant of the solvent = 1.86°C/m</em>
<em>m is molality of the solution (Moles of solute / kg of solvent)</em>
<em>And i is Van't Hoff constant (1 for a nonelectrolyte)</em>
Replacing:
0.400°C =1.86°C/m*m*1
0.400°C / 1.86°C/m*1 = 0.215m
As mass of solvent is 280.0g = 0.2800kg, the moles of the solute are:
0.2800kg * (0.215moles / 1kg) = 0.0602 moles of solute must be added.
The mass of ethylene glycol must be added is:
0.0602 moles * (62.10g / mol) =
3.74g of ethylene glycol must be added to decrease the freezing point by 0.400°C
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Answer:
for its one mole it is of 28gram. according to mole concept in one mole, there is 6.022*10^23 moles are present. so mass of 1 molecule of nitogen gas is 28/(6.022*10^23)
12 thousandth is the same as 0.012, so to put something in scientific notation you move the decimal point to the left or right until it is between the first two numbers. So:
Moving the decimal for 0.012 to between the first two numbers, we get: 1.2
For every move of the decimal place to get there, we divide/multiply by 10 each time. In this case, we multiply by 10 each time.
To get to 1.2, we had to move the decimal 2 times, so the answer is 1.2×10^-2
When you move the decimal to the right, the value of the power is negative, and when you move it to the left it is positive.
Answer:
The pH of a solution is a measure of the molar concentration of hydrogen ions in the solution and as such is a measure of the acidity or basicity of the solution.
