Answer:
The maximum pressure is 612.2 Pa
Explanation:
The pressure of the ice (P1) = 624 Pa
The temperature of the ice = 273.16 K
The maximum temperature the specimen = - 5 oC
= -5 + 273 = 268K
The maximum Pressure the freeze drying can be will be (P2) = ?
Using Pressure law, which shows the relationship between pressure and temperature.
P1 / T1 = P2 / T2
P2 T1 = P1 T2
P2 = P1 T2 / T1
P2 = 624 × 268 / 273.16
P2 = 612.2 Pa
The maximum pressure at which drying can be carried out is 612.2 Pa
Check the attached document more explanation. jjjjggggg
Answer:
3.6 times 10^4
Explanation:
Scientific notation is between 1-9. So, we move 36000 to 4 decimal places. SO it would be 3.6 times 10^4. Scientific Notation always has the base of 10 . Enjoy :)
The dissociation equation will be
NH4OH ---> NH4+ + OH-
Initial 0.006 0 0
Change -0.006 X 0.053 +0.006 X 0.053 -0.006 X 0.053
Equlibrium 0.006 -0.006 X 0.053 0.006 X 0.053 0.006 X 0.053
Ka = [NH4+] [ OH-] / [NH4OH] = (0.006 X 0.053)^2 / 0.006 -0.006 X 0.053
Ka = 1.78 X 10^-5
Answer:
Energy is released when bonds are broken, and energy is absorbed when bonds are formed.
The reaction is
CaC₂(s) + 2H₂O (l) -----> Ca(OH)₂ (s) + C₂H₂ (g)
As we have data of gas ethyne (or acetylene), C₂H₂
We can calculate the moles of acetylene and from this we can estimate the mass of calcium carbide taken
the moles of acetylene will be calculated using ideal gas equation
PV =nRT
R = gas constant = 0.0821 Latm/molK
T = 385 K
V = volume = 550 L
P = Pressure = 1.25 atm
n = moles = ?
n = PV /RT = 1.25 X 550 / 0.0821 X 385 = 21.75 mol
As per balanced equation these moles of acetylene will be obtained from same moles of calcium carbide
moles of calcium carbide = 21.75mol
molar mass of CaC₂ = 40 + 24 = 64
mass of CaC₂ = moles X molar mass = 21.75 X 64 = 1392g
