17

$\ce{SiCl_4}$ does not quite dissolve in water; rather, it reacts with water. So does $\ce{CCl_4}$, albeit extremely slowly, so for most purposes one may safely assume it doesn't. The difference is mostly due to the atomic size of C and Si. Smaller С atom is completely blocked off by four bulky chlorine atoms, so the water molecule can't reach it. Larger Si ...


10

A protonated carbonic acid (trihydroxymethyl cation) $\ce{H3CO3+}$ does exist, and is in fact incredibly stable in the solutions of superacids [1] up to $\pu{0 °C}.$ One way of obtaining $\ce{H3CO3+}$ is dissolving inorganic carbonates and hydrogen carbonates in magic acid at $\pu{-80 °C}$ [2]: $$\ce{CO3^2- or HCO3- ->[FSO3H-SbF5/SO2][\pu{-80 °C}] ...


10

Plants are able to store energy as carbohydrates, i.e. they can make more carbohydrates than they need for their metabolism when there is no sunlight, and store it for later use. So the amount of energy in your equations is not equal. Some plants are offering this stored energy as sugars as nectar or fruits in exchange for pollination and spreading their ...


7

Steric hindrance does indeed interfere with the stability of carbon tetraiodide, as does poor covalent bonding overlap between the very differently sized carbon and iodine atoms. Even so, carbon tetraiodide is definitely established and in use as an iodinating agent. Storage below normal room temperature is recommended. Carbon tetraiodide is also very red....


7

No, neither C nor Si have to be present in a polymer. IUPAC defines polymer simply as A substance composed of macromolecules. In turn, there is no limitations on the elements the macromolecules may consist of. In fact, there is an extensive class of inorganic polymers free of carbon and silicon.


7

Biomass The net production of $\ce{CO2}$ in all living organisms is close to zero. The argument is that if the total biomass on earth does not change over a period of time, and the net transfer from biomass to other reservoirs of carbon does not change much, the production and consumption should balance out. Wikipedia's article on biomass states: The total ...


5

Wikipedia reports that calculations show orthocarbonic acid spontaneously decomposes to the ordinary (meta)carbonic acid $\ce{H2CO3}$ plus water. However, orthocarbonate esters $\ce{C(OR)4}$ do exist. The orthoacid may, however, become stable at high pressure [1, with a nontechnical summary given in 2] and possibly exist within Uranus and Neptune. It is ...


4

According to the authors of Ref. 1 this is a general property. They provide an explanation for the stability of such sheets based on formation of particular buckled geometries: The discovery of a flat two-dimensional crystal known as graphene has contradicted Landau−Peierls−Mermin−Wagner arguments that there is no stable flat form of such crystals. Here, ...


4

Your second equation (respiration) happens less than your first equation (photosynthesis) while the plant is growing. About a third of the mass of a typical plant is cellulose, which is created by linking the glucose that is product of the first reaction. So the fact that you have a plant in front of you at all means that the plant has performed the first ...


3

This nomenclature is due to the fact that amino acids are carboxylic acids. Near the carboxylic acid moiety, the carbon chain is unbranched and simple, so the positions are named like an unbranched, simple aliphatic carboxylic acid. The carboxylic acid ($\ce{-CO2H}$) is not indicated with a position. But the carbon immediately next to it is $\alpha$. The ...


3

Actually a $\ce{Si-Cl}$ bond is much stronger than a $\ce{C-Cl}$ bond. It takes about 90 kcal/mole to break a $\ce{Si-Cl}$ bond, but only around 81 kcal/mole to break a $\ce{C-Cl}$ bond. The strengths of the corresponding $\ce{Si-O}$ (110 kcal/mole) and $\ce{C-O}$ (85 kcal/mole) bonds also need to be considered. In the silicon reaction we need 90 kcal/...


3

Answers: Consider the mass and kinetic energy of an electron or of an ion of nitrogen or oxygen, and the reactivity with carbon. Good question! It would be interesting to see the relative abundance of allotropes of carbon deposited from a filament in vacuo. There is a metallic glisten to the deposit, so there might be graphite, carbon nanotubes or ...


3

a for amorphous is totally correct. Also used in other publications like here.


2

$\ce{CO2}$ is emitted yes. It is not formed in the usual combustion manner however. There a likely two routes to $\ce{CO2}$ formation during wood pyrolysis. Either through the elimination of carboxyl groups e.g., $$\ce{PhCOOH -> Ph + CO2}\text{,}$$ or by a water gas shift reaction: $$\ce{H2O + CO -> CO2 + H2}\text{.}$$ My opinion is that the latter is ...


2

There is not many simple tests. One of possible tests would be passing gas through neutral solution of suitable acidobasic colour indicator, e.g bromthymol blue, turning green to yellow while getting slightly acidic. But it would not be specific, any acidic gas would do that. You have not mentioned context, why do you need to know ? Or is it just homework-...


2

The important thing to consider is the chemistry of carbon dioxide in water, forming carbonic acid. Note also that calcium hydroxide is at edge between being a strong or a weak base. $$\begin{align}\ \ce{CO2 ^ + H2O &<=> CO2 . H2O} \tag{1} \\ \ce{CO2 . H2O &<=> H2CO3} \tag{2} \\ \ce{H2CO3 &<=> H+ + HCO3^-} \tag{3} \\ \ce{HCO3^- ...


2

Generally, heavier atoms means lower specific stored charge per mass. Specific energy per mass depends of the cell redox systems, but also on the above. Silicium, in contrary to carbon, does not form hexagonal planar structure with delocalized electrons like graphite, but prefers the diamond-like structure. The Li-ion cell anode is formed by lithium-...


2

Question 1: Why is that one(in space) considered alpha and not the carbon atom next to it? All human proteins consist of $\alpha$-amino acid residues. An $\alpha$-amino acid means the carboxylic acid group ($\ce{COOH}$) and amino group ($\ce{NH2}$) are separated by one $\ce{C}$ carbom atom, which is called $\alpha$-carbon ($\ce{C}_\alpha$; See the insert at ...


1

Ions in solution [OP] I understand that ferrous chloride dissociates in water to $\ce{Fe^2+}$ and $\ce{Cl-}$ ions. Yes. The same goes for the iron(III) species. [OP] I'm told that iron(II) chloride loses electrons to the positive electrode and becomes iron(III) chloride. No, iron(II) loses electrons and becomes iron(III). The chloride is less ...


1

Pure silicon is not conducting like metals. It is an electrical insulator. But it becomes a semi-conductor if it is doped. And it is doped if a tiny amount (less than 1%) of some impurities is present in the crystal of silicon. So pure silicon cannot be used as an electrode, if it is pure. But it can with doped silicium.


1

Since both are metaloids, or semiconductors, look for the criteria that define them. In particular, electronegativity or ionization energy are important.


1

It would have been helpful if you have said what kind of polymer-based nanocomposites you would like to create. Yet, I found a good article for the fabrication of poly dimethylsiloxane/carbon nanofiber (CNF)-based nanocomposites. The schematic diagram of experimental procedure is illustrated in following figure (from the Ref. 1). The experimental section in ...


1

My worry is that the energy requirements for making soda lime, caustic soda or some other carbon dioxide adsorber will be so high that overall it will result in the emission of more green house gases. Years ago I was touring a waste disposal site where they react waste sulfuric acid with limestone. The boss of the site told me that some years ago someone ...


1

A silicon tetrachloride reacts with water, while carbon tetrachloride does not. This is due to the fact that the carbon does not have d-orbitals to accept lone pair of electron from water, while silicon has vacant d-orbitals to accept lone pair of electron from water.


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