Answer:
69.79 mmHg is the pressure for the solution
Explanation:
Formula for vapor pressure lowering:
Vapor pressure of pure solvent(P°) - Vapor pressure of solution (P') = P° . Xm
Xm → Molar fraction of solute (moles of solute / Total moles)
Total moles = Moles of solute + Moles of solvent
Let's determine the moles:
50.36 g . 1mol/342 g = 0.147 moles of sugar
88.69 g. 1mol/ 18g = 4.93 moles of water
Total moles = 0.147 + 4.93 = 5.077 moles
Xm = 0.147 / 5.077 = 0.0289
If we replace data given in the formula:
71.88 mHg - P' = 71.88 mmHg . 0.0289 . 0.0289
P' = - (71.88 mmHg . 0.0289 - 71.88 mmHg)
P' = 69.79 mmHg
Answer:
The initial temperature is 499 K
Explanation:
Step 1: Data given
initial volume = 12 cm3 = 12 mL
Final volume = 7 cm3 = 7mL
The final temperature = 18 °C = 291 K
Step 2: Calculate the initial temperature
V1/T1 = V2/T2
⇒with V1 = the initial volume = 0.012 L
⇒with T1 = the initial volume = ?
⇒with V2 = the final volume 0.007 L
⇒with T2 = The final temperature = 291 K
0.012 / T1 = 0.007 / 291
0.012/T1 = 2.4055*10^-5
T1 = 0.012/2.4055*10^-5
T1 = 499 K
The initial temperature is 499 K
In a physical change the form changes or the state of the matter. For instance water can freeze and water can melt, but it is still water.
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Answer:
Explanation:
In photoelectric effect , radiation of some energy is made to fall on metal plate which results in the ejection of electrons by the metal plate . The kinetic energy of electrons comes from the energy of radiation falling on metal plate . Some of energy of radiation falling on metal plate is used in the process of bringing the electron to the surface and it is called threshold energy . The radiation must have at least this energy to see to it that electrons are ejected . and the rest of the energy of radiation is used in imparting kinetic energy to the electron .
The red light radiation has least energy so it is least likely to eject electrons from metal plate and produce photoelectric effect .
The answer is most likely C
