
Density is defined as Mass per unit volume of an object ~
And hence, the correct choice is ~ 1


Molar mass helium gas :
He = 4.0 g/mol
number of moles: 3.75 / 4.0 => 0.9375 moles
1 mole ------ 22.4 ( at STP)
0.9375 ------ ?
volume = 0.9375 x 22.4 / 1
Volume = 21 / 1
Volume = 21 L
hope this helps!
The ionization equation is:
HF ⇄ H(+) + F(-)
The ionization constant is Ka = [H(+)] * [H(-)] / [HF]
=> [H(+)] * [F(-)] = Ka * [HF]
Given that Ka < 1
[H(+)] * [F(-)] < [HF]
Which is [HF] > [H(+)] * [F(-)] the option a. fo the list of choices.
[Co(CN)₆]³⁻ → Yellow
[Co(NH₃)₆]³⁺ → Orange
[CoF₆]³⁻ → Blue
Explanation:
- All the given compounds have octahedral geometry but the ligand in each are different with the same metal ion.
- Ligands strength order: CN⁻ > NH₃ > F⁻
- The ligand CN will act as a strong field ligand so that the splitting is maximum when compared to NH₃ and F⁻
- If the splitting is more, the energy required for transition is more, and the wavelength is inversely proportional to energy.
- So CN complex will absorb at lower wavelength (yellow color)
If I remember correctly, it would be B. A very large amount of energy is produced from a tremendous mass.