Answer:
0, l is n-1 always, ml is l to -l
Answer: 0.028 grams
Explanation:
Depression in freezing point :
Formula used for lowering in freezing point is,
![\Delta T_f=k_f\times m](https://tex.z-dn.net/?f=%5CDelta%20T_f%3Dk_f%5Ctimes%20m)
or,
![\Delta T_f=k_f\times \frac{\text{ Mass of solute in g}\times 1000}{\text {Molar mass of solute}\times \text{ Mass of solvent in g}}](https://tex.z-dn.net/?f=%5CDelta%20T_f%3Dk_f%5Ctimes%20%5Cfrac%7B%5Ctext%7B%20Mass%20of%20solute%20in%20g%7D%5Ctimes%201000%7D%7B%5Ctext%20%7BMolar%20mass%20of%20solute%7D%5Ctimes%20%5Ctext%7B%20Mass%20of%20solvent%20in%20g%7D%7D)
where,
= change in freezing point
= freezing point constant (for benzene} =![5.12^0Ckg/mol](https://tex.z-dn.net/?f=5.12%5E0Ckg%2Fmol)
m = molality
Putting in the values we get:
![0.400^0C=5.12\times \frac{\text{ Mass of solute in g}\times 1000}{354.5\times 209.0}](https://tex.z-dn.net/?f=0.400%5E0C%3D5.12%5Ctimes%20%5Cfrac%7B%5Ctext%7B%20Mass%20of%20solute%20in%20g%7D%5Ctimes%201000%7D%7B354.5%5Ctimes%20209.0%7D)
![{\text{ Mass of solute in g}}=0.028g](https://tex.z-dn.net/?f=%7B%5Ctext%7B%20Mass%20of%20solute%20in%20g%7D%7D%3D0.028g)
0.028 grams of DDT (solute) must be dissolved in 209.0 grams of benzene to reduce the freezing point by 0.400°C.
Answer: A pressure of 0.681 atm would be exerted by 0.023 grams of oxygen
if it occupies 31.6 mL at
.
Explanation:
Given : Mass of oxygen = 0.023 g
Volume = 31.6 mL
Convert mL into L as follows.
![1 mL = 0.001 L\\31.6 mL = 31.6 mL \times \frac{0.001 L}{1 mL}\\= 0.0316 L](https://tex.z-dn.net/?f=1%20mL%20%3D%200.001%20L%5C%5C31.6%20mL%20%3D%2031.6%20mL%20%5Ctimes%20%5Cfrac%7B0.001%20L%7D%7B1%20mL%7D%5C%5C%3D%200.0316%20L)
Temperature = ![91^{o}C = (91 + 273) K = 364 K](https://tex.z-dn.net/?f=91%5E%7Bo%7DC%20%3D%20%2891%20%2B%20273%29%20K%20%3D%20364%20K)
As molar mass of
is 32 g/mol. Hence, the number of moles of
are calculated as follows.
![No. of moles = \frac{mass}{molar mass}\\= \frac{0.023 g}{32 g/mol}\\= 0.00072 mol](https://tex.z-dn.net/?f=No.%20of%20moles%20%3D%20%5Cfrac%7Bmass%7D%7Bmolar%20mass%7D%5C%5C%3D%20%5Cfrac%7B0.023%20g%7D%7B32%20g%2Fmol%7D%5C%5C%3D%200.00072%20mol)
Using the ideal gas equation calculate the pressure exerted by given gas as follows.
PV = nRT
where,
P = pressure
V = volume
n = number of moles
R = gas constant = 0.0821 L atm/mol K
T = temperature
Substitute the value into above formula as follows.
![PV = nRT\\P \times 0.0316 L = 0.00072 mol \times 0.0821 L atm/mol K \times 364 K\\P = \frac{0.00072 mol \times 0.0821 L atm/mol K \times 364 K}{0.0316 L}\\= 0.681 atm](https://tex.z-dn.net/?f=PV%20%3D%20nRT%5C%5CP%20%20%5Ctimes%200.0316%20L%20%3D%200.00072%20mol%20%5Ctimes%200.0821%20L%20atm%2Fmol%20K%20%5Ctimes%20364%20K%5C%5CP%20%3D%20%5Cfrac%7B0.00072%20mol%20%5Ctimes%200.0821%20L%20atm%2Fmol%20K%20%5Ctimes%20364%20K%7D%7B0.0316%20L%7D%5C%5C%3D%200.681%20atm)
Thus, we can conclude that a pressure of 0.681 atm would be exerted by 0.023 grams of oxygen
if it occupies 31.6 mL at
.
Answer:
(☞ ಠ_ಠ)☞
Newton's. first law of motion states that "Everybody continues in its state of rest or uniform motion in a straight line unless it is acted by some external forces".
Explanation:
hope it helps
good day
tysm (≧▽≦)
Three complete orders on each side of the m=0 order can be produced in addition to the m = 0 order.
The ruling separation is
d=1 / (470mm −1) = 2.1×10⁻³ mm
Diffraction lines occur at angles θ such that dsinθ=mλ, where λ is the wavelength and m is an integer.
Notice that for a given order, the line associated with a long wavelength is produced at a greater angle than the line associated with a shorter wavelength.
We take λ to be the longest wavelength in the visible spectrum (538nm) and find the greatest integer value of m such that θ is less than 90°.
That is, find the greatest integer value of m for which mλ<d.
since d / λ = 538×10⁻⁹m / 2.1×10 −6 m ≈ 3
that value is m=3.
There are three complete orders on each side of the m=0 order.
The second and third orders overlap.
Learn more about diffraction here : brainly.com/question/16749356
#SPJ4