Displacement reaction is a chemical reaction in which a more reactive element displaces a less reactive element from its compound. Both metals and non-metals take part in displacement reactions. Example : Reaction of iron nails with copper sulphate solution.
Answer:
(D) (CH3CH2)2NH
Explanation:
In order to decide which base is strongest we need to calculate its PKb
PKb = -log [Kb]
A large Kb value and small PKb value gives the strongest base
Compound Kb PKb
(A) C6H5NH2 - 4 x 10^-10 9.349
(B) NH3 1.76x 10^-5 4.754
(C) CH3NH2 4.4x 10^-4 3.357
(D) (CH3CH2)2NH 8.6x 10^-4 3.066
(E) C5H5N 1.7x10^-9 8.77
Clearly (CH3CH2)2NH is the strongest base.
For a wave, speed= frequency x wavelength
Answer:
An increase in temperature indicates that the molecules of gas speed up.
Explanation:
The molecular kinetic theory states that the average kinetic energy of gas particles (molecules) is proportional to the absolute (Kelvin) temperature of the gas, and all gases at the same temperature have the same average kinetic energy.
Therefore, as the temperature increases so the kinetic energy increases.
It is also known that the kinetic energy is proportional to the squared speed of the particles, therefore the higher the kinetic energy the average speed of the molecules:
- higher temperature → higher kinetic energy → higher average speed
We can use the ideal gas law equation to find the pressure
PV = nRTwhere
P - pressure
V - volume - 2.6 x 10⁻³ m³
n - number of moles - 0.44 mol
R - universal gas constant - 8.314 Jmol⁻¹K⁻¹
T - temperature - 25 °C + 273 = 298 K
substituting the values into the equation,
P x 2.6 x 10⁻³ m³ = 0.44 mol x 8.314 Jmol⁻¹K⁻¹ x 298 K
P = 419 281.41 Pa
101 325 Pa is equivalent to 1 atm
Therefore 419 281.41 Pa - 1/ 101 325 x 419 281.41 = 4.13 atm
Pressure is 4.13 atm
