Answer is: the approximate freezing point of a 0.10 m NaCl solution is -2x°C.
V<span>an't
Hoff factor (i) for NaCl solution is approximately 2.
</span>Van't Hoff factor (i) for glucose solution is 1.<span>
Change in freezing point from pure solvent to
solution: ΔT = i · Kf · m.
Kf - molal freezing-point depression constant for water is 1,86°C/m.
m - molality, moles of solute per
kilogram of solvent.
</span>Kf and molality for this two solutions are the same, but Van't Hoff factor for sodium chloride is twice bigger, so freezing point is twice bigger.
They can be stopped by a piece of paper.
A hypothesis is how you think the experiment is going to end
Answer:
The correct answer is 399.8 ppm
Explanation:
A concentration in parts per million (ppm) is equal to:
Solute: Cd; Mass = 180 mg x (1 g/1000 mg) = 0.18 g
Solvent: Water ; Mass= 450.0 g x (1 kg/1000 g) = 0.45 kg
We have the following total mass of solution:
Mass of solution = Mass of solute + Mass of solvent = 0.18 g + 450 g = 450.18 g = 0.45018 kg
Finally, we divide the <u>mass of solute (in mg)</u> into the <u>mass of solution (in kg)</u> to obtain the ppm (in mg/Kg):
ppm = 180 mg/0.45018 kg = 399.8 mg/Kg = 399.8 ppm
What poison ivy looks like:
Each leaf has 3 little leaflets. It tends to grow off-white berries on the leaves in the early fall, and grows yellow-green flowers in the spring.
Treating poison ivy:
If you have a rash from poison ivy, it is recommended to rinse your skin off with lukewarm water immediately after you notice the rash.
Make sure to wash your clothing since the oil from the plant can stick to your clothing.
Do not scratch at the rash, as scratching will cause an infection.
If blisters appear on your skin, do not mess with them as it can prevent infection.
How to kill poison ivy:
If you find the plant, do not pull or burn it. Even if you pull it, it will still grow out of the ground since you did not eliminate the roots of it. Burning it can release <span>urushiol into the air which can be harmful.
</span>It is recommended to use a specialized weed killing spray. Always look at the ingredients in the spray and look for: Triclopyr, which fights through the surface of the plant, and also <span>glyphosate, that helps kill the roots of the plant.
</span>Once you use a spray, it will take 1-2 weeks for it to die. It will eventually turn yellowish-brownish.
Important:
Poison ivy contains urushiol which can cause allergic reaction.
Burning poison ivy releases urushiol into the air which can also cause allergic reaction and can be harmful.
