Which formula represents a polar molecule? (1) O2 (2) CO2 (3) NH3 (4) CH4
1 answer:
Answer: Option (3) is the correct answer.
Explanation:
A molecule is polar when the net dipole moment of molecule is zero. When an electronegative atom is attached to an electropositive atom then the electronegative atom pulls the shared pair of electrons more towards itself.
As a result, the movement of electrons is more towards the electronegative atom and the dipole moment becomes zero. This will also induce partial positive and partial negative charge on electropositive and electronegative atom.
On the other hand, are covalent compounds and does not have a net zero dipole moment.
Thus, we can conclude that out of the given options represents a polar molecule.
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The temperature of the gas sample is 813 K.
<u>Explanation:</u>
We have to use the ideal gas equation to find the temperature of the gas sample.
The ideal gas equation is PV = nRT
Pressure, P = 429 mm Hg = 0.56 atm
Volume, V = 560 mL = 0.56 L
R = gas constant = 0.08205 L atm mol⁻¹K⁻¹
Mass = 0.211 g
Molar mass of carbon di oxide = 44.01 g / mol
Moles, n =
= 0.0047 mol
Now, we have to plugin the above values in the above equation, we will get the temperature as,
T =
= 813 K
So the temperature of the gas sample is 813 K.
Answer:
Explanation:
count given by old sample = .97 disintegrations per minute per gram
count given by fresh sample = 6.68 disintegrations per minute per gram
Half life of radioactive carbon = 5568 years
rate of disintegration
dN / dt = λ N
In other words rate of disintegration is proportional to no of radioactive atoms present . As number reduces rate also reduces .
Let initial no of radioactive be N₀ and after time t , number reduces to N
N₀ / N = 6.68 / .97
Now
λ is disintegration constant
λ = .693 / half life
= .693 / 5568
= .00012446 year⁻¹
Putting the values in the equation above
1.929577 = .00012446 t
t = 15503.6 years .