Answer: 770 g water are needed to dissolve 27.8 g of ammonium nitrate 
in order to prepare a 0.452 m solution
Explanation:
Molality : It is defined as the number of moles of solute present per kg of solvent
Formula used :
where,
n= moles of solute
Moles of 
= weight of the solvent in g = ?
Thus 770 g water are needed to dissolve 27.8 g of ammonium nitrate in order to prepare a 0.452 m solution
Answer:
0.011 moles
Explanation:
There are about 6.02*10^23 atoms in a mole, so in the given sample, there are
which is about 0.011 moles.
Answer: I am actually studying about Stars, so I got you.
3. As the temperature of a star Increases, it's luminosity increases.
As the temperature of a star decreases, it's luminosity decreases.
4. Hot and Bright. The bigger the star, the hotter it gets is from what I learned.
Answer:
The correct answer is 25 mL graduated cylinder (it should be used in all the cases)
Explanation:
In order to measure 25.00 ml sample of a solution it should be used a 25 mL graduated cylinder, as it is previously and properly calibrated. The other laboratory glassware, beaker and erlenmeyer, have graduations which are approximate, so they are used when exact volumes are not needed.
ii) graduated cylinder has the least uncertainly. It is more accurate than a beaker or erlenmeyer (to within 1%)
iii) A 25 mL graduated cylinder should be used because it is the most accurate lab glassware (between those were mentioned: beaker, erlenmeyer).
We will use the expression for freezing point depression ∆Tf
∆Tf = i Kf m
Since we know that the freezing point of water is 0 degree Celsius, temperature change ∆Tf is
∆Tf = 0C - (-3°C) = 3°C
and the van't Hoff Factor i is approximately equal to 2 since one molecule of KCl in aqueous solution will produce one K+ ion and one Cl- ion:
KCl → K+ + Cl-
Therefore, the molality m of the solution can be calculated as
3 = 2 * 1.86 * m
m = 3 / (2 * 1.86)
m = 0.80 molal
