Answer:
- 0.99 °C ≅ - 1.0 °C.
Explanation:
- We can solve this problem using the relation:
<em>ΔTf = (Kf)(m),</em>
where, ΔTf is the depression in the freezing point.
Kf is the molal freezing point depression constant of water = -1.86 °C/m,
m is the molality of the solution (m = moles of solute / kg of solvent = (23.5 g / 180.156 g/mol)/(0.245 kg) = 0.53 m.
<em>∴ ΔTf = (Kf)(m)</em> = (-1.86 °C/m)(0.53 m) =<em> - 0.99 °C ≅ - 1.0 °C.</em>
Answer:
B. CH3Br
Explanation:
Dipole -Dipole interactions take place in polar molecules.
CH3Br exhibits dipole -dipole forces as its strongest attraction between molecules because it is a polar molecule due to the slightly negative dipole present on the Br molecule.
While O2 is a nonpolar molecule due to its linear structure, CCl4 has zero resultant dipole moment, Helium is non-polar and BrCH2CH2OH is a non polar compound having net dipole moment is zero.
Hence, the correct option is B. CH3Br.
Answer:
14.7 lbs
Explanation:
Air pressure is the weight of the air above us. It is approximately 14.7 pounds or lbs per square inch at sea level. It means that an air column weights 14.7 lbs, 1 square inch in diameter, reaching all the way up to the top of the atmosphere.
Answer:
A Neutron and a Hydrogen Atom
Explanation:
Hydrogen atom having an atomic mass of 1.008 amu consists of one proton and one electron. Hence, the +ve and -ve charges cancels out and makes the hydrogen atom a neutral specie.
Also, we know that neutron is neutral sub particle while, proton and electron are positively and negatively charged respectively. Therefore, a neutral neutron having no charge becomes equal to hydrogen atom having zero charge due to cancellation of both +ve and -ve charges.
PV = nRT —> P = nRT/V
n = 0.250 moles of gas
R = 0.08206 L atm / mol K
T = 18 + 273 = 291 K
V = 7.50 L
P = (0.250)(0.08206)(291)/(7.50) = 7.96 atm
