3

We can split the reaction $$\ce{H2O2 -> H2O + O2}$$ into the respective reduction and oxidation half-reactions. $$\ce{H2O2 -> O2 + 2H+ + 2e-}$$ $$\ce{H2O2 + 2H+ + 2e- -> 2H2O}$$ Since the n-factor of $\ce{H2O2}$ for both these half-reactions is 2, the n-factor is: $$\frac{1}{n_f} = \frac{1}{2} + \frac{1}{2} = 1$$ $$n_f = 1$$ Based on the comments ...


3

Yes, there is. The following is a plot of the hydration enthalpy versus row in the Periodic Table. Data was extracted from the Wikipedia, not the primary source (Ref 1). Your thinking is right. The hydration entropy is evidently negative due to structuring of water (including loss of rotational degrees of freedom), becoming less negative for the larger ions (...


2

The solubility product of $\ce{PbSO4}$ is about $10^{-8}$. Now suppose $[\ce{Pb^{2+}}$] falls down from $\pu{1 M}$ to an arbitrary low value like $\pu{10^{-8} M},$ due to addition of $\ce{SO4^{2-}}$ ions. In this case, Nernst's law can be applied, and the potential of the lead electrode falls from $E^\circ_\ce{Pb} = \pu{-0.13 V}$ down to $$E_\ce{Pb} = \pu{-0....


1

I want to elaborate the answer of Ashish Ahuja because he is also perplexed by the n-factors. First of all for general readers n-factors are of historical interest only. Due to my interest in historical analytical methods, the following points would clarify this situation: A) Equivalent weights do not require any knowledge of molarity, moles, electrons ...


1

Air reacting with charcoal will produce $\ce{N2},$ $\ce{CO}$ and $\ce{CO2}.$ $\ce{CO2}$ will be absorbed by calcium hydroxide or sodium hydroxide. However, $\ce{CO}$ cannot be absorbed at ordinary temperatures and pressures. Only at $\pu{200 °C}$ and $\pu{10 atm},$ it reacts with $\ce{NaOH}$ to produce sodium formate $\ce{HCOONa}.$ Finally, $\ce{CO}$ can be ...


1

I understand your assumption of selenium disulfide being a simple molecular like that. It is similar to the mistake of silicon dioxide, which at first glance we might assign it to be a linear molecule like carbon dioxide. However the crystal structure of silicon dioxide is far more complex. In selenium disulfide, the selenium and sulfur atoms form a 8-...


1

Given the whitening observed at the cathode, one potential explanation is that calcium salts were precipitating there, forming a layer blocking passage of part of the current. I usually write the cathodic hydrogen-evolution reaction in neutral solution as: $$ \ce{2 H2O + 2 e- -> H2 + 2OH-} $$ Thus, the pH in the vicinity of the cathode will be ...


1

Ligands that produce a large splitting are called strong field ligands, and those that produce a small splitting are called weak field ligands. So when crystal spittling occurs and of the 2 ligands, the one which causes greater splitting is a strong field ligand. So the strength of the ligand can be found by experimental ways . Or you to be able to decide ...


1

The way to tackle this is to look at the lone pair repulsions between the 2 molecules. It is known that $\ce{N-N};$ $\ce{O-O};$ $\ce{F-F}$ single bonds are quite unstable due to lone pair (lp) repulsions. An evidence of this is that $\ce{N}$ exists in molecular state as $\ce{N2}$ using multiple bonds, so that it's lone pairs do not repel each other, however $...


1

This question and the one referenced by Mithoron address NH$_4$HF$_2$ as an entity in itself which must be examined as a whole. It is easier conceptually to rewrite the formula for the compound as NH$_4$F.HF. Consider adding NH$_4$F to water: you get a pH near 7. In a separate container, add HF to water (~0.1 M); you get a pH ~1 https://ehs.princeton.edu/...


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