B. False
It was created in 1869
Answer:
The meaning and usefulness of the mole Page 2 2 • One mole of NaCl contains 6.022 x 1023 NaCl formula units. Use the mole quantity to count formulas by weighing them.
Answer:
shorter than
equal to
Explanation:
Let us go back to the Einstein photoelectric equation;
KE = E - Wo
Where
KE = kinetic energy of the photoelectron
E = energy of the incident photon
Wo = work function of the metal
But KE = 1/2mv^2
Thus the velocity of the emitted photoelectron is determined by the kinetic energy of the emitted photoelectron.
Since the work function of metal A is smaller than that of metal B, the kinetic energy of photoelectrons emitted from metal A is greater than that of photoelectrons emitted from metal B . Therefore, the velocity of electrons from metal A is greater than those from metal B.
From de Broglie relation;
λ = h/mv
Where;
λ = de Broglie wavelength
h = Plank's constant
m = mass
v = velocity
Metal A producing electrons with greater velocity will lead to a shorter de Broglie wavelength compared to those from metal B.
The number of photoelectrons ejected is determined by the intensity of the photons and not the energy of the incident photons or the work function of the metals. Since the two metals are exposed to the the same laser, equal number of photoelectrons are produced for metals A and B.
Answer:
The dispersed particles are spread evenly throughout the dispersion medium, which can be a solid, liquid, or gas. Because the dispersed particles of a colloid are not as large as those of a suspension, they do not settle out upon standing.
Explanation:
Answer:
pH of soltion will be 5.69
Explanation:
The pH of the solution will be due to excessive acid left and the salt formed. Thus, it will form a buffer solution.
The pH of buffer solution is calculated from Henderson Hassalbalch's equation, which is:
![pH=pKa+log(\frac{[salt]}{[acid]} )](https://tex.z-dn.net/?f=pH%3DpKa%2Blog%28%5Cfrac%7B%5Bsalt%5D%7D%7B%5Bacid%5D%7D%20%29)
The moles of acid taken :
The moles of base taken:
The moles of acid left after reaction :
The moles of salt formed = 4.5mmol
Putting values in equation
![pH=pKa+log(\frac{[salt]}{[acid]} )=4.74+log(\frac{4.5}{0.5})=5.69](https://tex.z-dn.net/?f=pH%3DpKa%2Blog%28%5Cfrac%7B%5Bsalt%5D%7D%7B%5Bacid%5D%7D%20%29%3D4.74%2Blog%28%5Cfrac%7B4.5%7D%7B0.5%7D%29%3D5.69)
