Answer:
the mole fraction of Gas B is xB= 0.612 (61.2%)
Explanation:
Assuming ideal gas behaviour of A and B, then
pA*V=nA*R*T
pB*V=nB*R*T
where
V= volume = 10 L
T= temperature= 25°C= 298 K
pA and pB= partial pressures of A and B respectively = 5 atm and 7.89 atm
R= ideal gas constant = 0.082 atm*L/(mol*K)
therefore
nA= (pA*V)/(R*T) = 5 atm* 10 L /(0.082 atm*L/(mol*K) * 298 K) = 2.04 mole
nB= (pB*V)/(R*T) = 7.89 atm* 10 L /(0.082 atm*L/(mol*K) * 298 K) = 3.22 mole
therefore the total number of moles is
n = nA +nB= 2.04 mole + 3.22 mole = 5.26 mole
the mole fraction of Gas B is then
xB= nB/n= 3.22 mole/5.26 mole = 0.612
xB= 0.612
Note
another way to obtain it is through Dalton's law
P=pB*xB , P = pA+pB → xB = pB/(pA+pB) = 7.69 atm/( 5 atm + 7.89 atm) = 0.612
A scientist would measure the amount of carbon-14 (¹⁴C) in a fossil to determine its age.
The ¹⁴C:¹²C ratio is constant in living organisms. When they die, the radioactive ¹⁴C decays, so the ratio changes. The half-life for the for the decay is 5730 a, so scientists can work backwards and calculate how long ago the plant died. The method is good for determining the age of fossils up to 50 000 a old.
Answer:
Explanation:
<u>a. Determine the number of valence electrons for each atom in the molecule</u>
<u />
In this case we both atoms are halogens. Therefore we will have 7 electrons for each atom.
<u>b. Draw the Lewis Dot structure </u>
<u />
In this case, the formula is 
, so the central atom would be "I" and the "Cl" atoms would be placed around "I". See figure 1
<u>c. Describe why the molecule is drawn this way (i.e. any extra rules/steps needed?)</u>
<u />
In this specific case, the "I" atom don't follow the octet rule. We will have an expanded octet for iodine (more than 8 electrons).
<u>d. Show the polarity of each bond and for the molecule by drawing in the dipole +d</u>
<u />
The negative dipole would be placed in the atom with higher electronegativity, in this case "Cl". The positive dipole would be placed in the atom with low electronegativity, in this case "I".
<u>I hope it helps!</u>
