Questions tagged [alkali-metals]

For questions about the alkali metals (group 1), their compounds, and their physical and chemical properties. For questions specifically about hydrogen, use tag [hydrogen] instead.

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Ionic mobilities and conductivities of lithium and potassium cations in acetonitrile–propylene carbonate solution

Recently I calculated the ionic mobility and molar ionic conductivity values for $\ce{Li+}$ and $\ce{K+}$ cations in an acetonitrile–propylene carbonate binary mix solution (8:2 molar fraction ratio). ...
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47 views

Why does conductivity of a solution of sodium in liquid ammonia decrease with a decrease in temperature?

What happens to the conductivity when a solution of sodium in liquid ammonia at $\pu{-33^{\circ}C}$ (Boiling point of ammonia) is further cooled? I expected the solution to behave as any other ...
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29 views

Can alkali-doped exohedral fullerene molecules show superconducivity?

Alkali doped fullerenes are one of the few organic materials that show superconductivity. However, when attaching a new molecular system to a fullerene doped with an alkali metal, will it still show ...
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156 views

Why is potassium less dense than sodium?

Potassium has a density of $\pu{0.86g/cm3}$ and sodium has a density of $\pu{0.97g/cm3}$,even though potassium is below sodium and one might expect the alkali metals to exhibit monotonously increasing ...
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25 views

What determines the consistency of hydrogen foam when reacting aluminium with sodium hydroxide solution?

I was using $\ce{NaOH}$ solution to remove hardened grease from my stove burners, and it began to generate a lot of bubbles, some of which merged into a big bubble and erupted into the surface, but ...
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26 views

Reason for sodium chloride to show colour in flame test [duplicate]

My textbook states the following: The alkali metals and their salts impart characteristic colour to an oxidizing flame. This is because the heat from the flame excites the outermost orbital electron ...
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54 views

Significance of p functions in compounds of the lighter alkaline and alkaline earth metals [closed]

It is often said that lithium follows the duet rule instead of the octet rule, unlike the more "usual" main-group elements. My question is the following: Does this hold for $\ce{Be, Na}$ and ...
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1answer
89 views

Do all metal nitrates give nitrogen dioxide on decomposition?

Some metal nitrates decompose to give nitrites: $\ce{2MNO3 -> 2MNO2 + O2}$ whereas some metal nitrates decompose to give $\ce{NO2}$. A possible reaction is $\ce{M(NO3)2 -> MO + NO2 + O2}$ Based ...
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1answer
116 views

What is the mechanism of formation of alkali metal superoxide?

I was studying about alkali metals. I can get how oxides and peroxides are formed. In alkali metal oxides, both of the bonds of the dioxygen molecule first undergoes homolytic cleavage, then the ...
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51 views

Color of Flame Test for Alkali Metals

Lithium is known to have the highest ionization energy among Group 1 elements. Also, characteristic colours in the flame test arise due to the excitation and de-excitation of electrons. Then why ...
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Can you get potassium by reducing KCl with lithium?

I would have said that the answer was no, because lithium is less reactive than potassium is, so you would expect the reaction to go the other way: with potassium and lithium chloride reacting to ...
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2answers
132 views

why do we see characteristic colors of alkali metals in oxidizing flame?

I am a high school student and I am a little confused in a topic, My confusion is that: We know alkali metals and their salts imparts characteristic color in oxidizing flame, for example: Lithium ...
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1answer
87 views

How to read mutual solubility curves of salts with a common ion?

Came across a few graphs that represent the mutual solubility of two compounds in a solvent, for e.g., solubility of $\ce{KCl}$, and $\ce{NaCl}$ in $\ce{H2O}$. On these particular graphs, I can see $x$...
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2k views

Wavelengths of colors emitted by alkali metals during flame test

While reading my NCERT chemistry book (Pg no.-300), I came across a table that mentions colors emitted by alkali metals and corresponding wavelengths. It mentions that Potassium emits violet color(...
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27 views

Why do neutral metal atoms have affinity towards electrons? [duplicate]

Since first electron affinity is almost always negative, neutral atoms of most elements (including metals) must have an affinity towards electron. But shouldn't metals want to lose electron(s) rather ...
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2answers
789 views

Why is density of chloroform greater than water?

Hydrocarbons (i.e., molecules containing carbon and hydrogen only) are generally less dense than water. Yet chloroform, which is a halogenated hydrocarbon, is more dense. Why is this? I know water ...
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1answer
584 views

Do alkali metals react with ammonia to form hydrogen gas?

I was recently studying about s-block alkali metals and I found the following reaction: $$\ce{\underset{alkali\\ metal}{M\phantom{_y}} + \underset{solution}{$(x +y)$ NH3} -> \underset{ammoniated\\ ...
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1answer
152 views

Hydrolysis of alkali and alkaline earth metals

Which of the following cations are not hydrolysed in aqueous solution? 1) $\ce{Mg^2+}$ 2) $\ce{Ca^2+}$ 3) $\ce{Na+}$ 4) $\ce{K+}$ I thought nothing would undergo hydrolysis, so all the options would ...
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226 views

Does Potassium Superoxide also absorb Carbon Monoxide?

Potassium Superoxide ($\ce{KO2}$) is used as an oxygen provider and carbon dioxide scrubber in life support systems $$\ce{2KO2 + H2O -> 2KOH + O2} \\ \ce{2KOH + CO2 -> K2CO3 + H2O}$$ I ...
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2answers
40 views

If acid releases proton then how can a proton react with another proton to form hydrogen gas? [duplicate]

As we know that acid releases proton (H+ ion) when dipped in water hydrogen has a proton and electron only . To form H+ hydrogen releases 1 electron and it becomes proton. But when Acid reacts with ...
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82 views

Why does solubility of Carbonate salts of Alkali metals in water increase down the group?

Carbonate salts have a very large anion so hydration energy should dominate over lattice energy. Since hydration energy is inversely proportional to radius of ion, I would expect Lithium to release ...
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1answer
140 views

Distinguishing between potassium chloride and sodium chloride

I have these very large blocks of salt intended for a water softener in my house, but I'm not sure if they're potassium chloride or sodium chloride, according to what I've read they're both widely ...
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2answers
120 views

Boiling Soda Reaction - Does It work? [closed]

I've come across a series of reactions, where $$\ce{2NaHCO3 <=> Na2CO3 + H2O + CO2}$$ at temperatures above 50 degrees Celsius, and $$\ce{Na2CO3 + H2O <=> NaHCO3 + NaOH}$$ I Have 3 ...
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1answer
3k views

What is the trend of thermal stability of group 1 oxides?

The thermal stability of most compounds of Group 1 elememts (hydroxides, carbonates, nitrates) increases down the group due to decrement in charge density of the cation. Now, according to one of my ...
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554 views

Do metals react with ammonia gas (not liquid phase)?

In my chemistry notes I have two chemical equations as follows: $$ \begin{align} \ce{2 NH3(g) + 6 Li(s) &-> 2 Li3N(s) + 3 H2(g)}\tag{R1} \\ \ce{2 NH3(g) + 2 Na(s) &-> 2 NaNH2 + H2(g)}\...
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1answer
96 views

Some substances appear white when crushed while others do not. Why?

Calcite crystals are semi-transparent but turn white when crushed. I used to think that it has something to do with the scattering of all wavelengths of light from small particles. But that cannot be ...
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1answer
96 views

What reaction could rubidium undergo in a vacuumed chamber with Macor ceramic and glass?

In the center of the chamber on the photo below you can see the hexagonally-shaped Macor glass-ceramic consisting of Silicon dioxide $\ce{SiO2}~46\%$ Magnesium dioxide $\ce{MgO}~17\%$ Aluminum ...
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1answer
822 views

The boiling points of Alkali metal group

As I know, the melting points of Alkali metals decrease down to the group due to decreasing of the energy of the metallic bond. But according to my understanding, after it has become to liquid the ...
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1answer
476 views

How to obtain sodium oxide from sodium chloride?

Under what conditions can $\ce{Na2O}$ be made from $\ce{NaCl}?$ I know $\ce{NaCl}$ doesn't oxidise under normal ambient conditions, but in the presence of what temperature and pressure ranges is this ...
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349 views

Volatile alkali metal compounds

Most elements are or have compounds that are gases or have a significant vapor pressure at room temperature. Fluoride is a powerful tool for producing highly oxidized covalent and volatile compounds. ...
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27 views

Make Na or K using carbonate + charcoal?

In the 19th century, Na metal was isolated by heating up Na2CO3 + carbon to 1200 C and distilling and capturing the Na vapor under oil. I tried it a few years ago with a small steel tube welded at ...
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5k views

Why does concentration of solutions of alkali metals in liquid ammonia change the magnetic properties?

In "NCERT Chemistry for Class XI - Volume II", in chapter "s-block elements", under the topic "Chemical Properties of alkali metals", it is given: (vi) Solutions in ...
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284 views

Sodium + water reaction, noxious fumes?

I was reacting pure sodium and tap water, and at one point I put some splattered sodium back into the water. I observed fumes that reacted with my respiratory system, producing a burning sensation. I ...
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257 views

Nature of the bonding in hexaaquaaluminium complex

$\ce {[Al(H2O)6]^3+}$ is a well-known complex ion formed by the $\ce {Al^3+}$. I have always had the understanding that only the aqua complexes of transition metal ions, such as $\ce {[Fe(H2O)6]^3+}$, ...
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657 views

Would dissolving Mg in NH3 help me purify Mg from all elements other than Li, Na, K, Rb, Cs, Fr, Ca, Sr, Ba, Eu and Yb? [closed]

According to Wikipedia all of the alkali metals, as well as $\ce{Ca, Sr, Ba, Eu,}$ and $\ce{Yb}$ (also $\ce{Mg}$ using an electrolytic process[4]), dissolve in ammonia to give the characteristic blue ...
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1answer
118 views

Hydration, Coordinate Bonding, and Reduction Potential in Groups 1 and 2 Elements [closed]

Whenever an alkali metal such as Lithium is hydrated/solvated, coordinate bonding occurs and it is the high hydration enthalpy of lithium which makes it the strongest reducing agent in aqueous ...
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1answer
2k views

Reaction of potassium with water

In general, when we put potassium into water, it will produce potassium hydroxide and hydrogen: $\ce{2K + 2H2O ⟶2KOH + H2}$ However isn't the following reaction also possible? $\ce{2K + H2O ⟶K2O + ...
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1answer
318 views

What's the densest alkali metal?

This was asked in a school exam of mine, GCSE curriculum, exactly as it was worded on the title. I found this question a bit vague, and answered it francium, however of course francium is just an ...
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295 views

What is the pale green solution from dissolving sodium hydroxide in a stainless steel flask?

I have previously used drain/sink cleaner gel based on sodium hydroxide but noticed that caustic soda crystals were a lot cheaper. I decided to experiment with making my own cleaner. I bought a 1 ...
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1answer
190 views

Are there known compounds of caesium with oxidation number >1?

Given that the left neighbor of caesium, xenon, does have fluorides and oxides, it is not inconceivable that caesium can have oxides or fluorides with an oxidation number higher than 1. Are such ...
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68 views

Why is the reason for color different in these two cases? [closed]

I have read in a book (NCERT India) about flame color for salts of alkali metal and color of transition metal complexes. In the first case, it says that during excitation of electrons to higher ...
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99 views

Potassium ethoxide

Is it possible to make potassium ethoxide by mixing $\ce{KOH}$ and $\ce{EtOH}$ in the presence of a dehydrating agent like $\ce{MgSO4}$ or $\ce{CaO}$ or $\ce{K2CO3}$? The easy way is adding metallic ...
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190 views

Flame Test Spectrograms Not Lining Up With Reality

In my AS Level chemistry class we had tried some DIY spectroscopy of flame tests with the aim of identifying anions in certain salts. We got as far as building the spectrometer inspired by Paper Craft ...
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1answer
135 views

Does aluminum oxide react with rubidium?

I have rubidium vapor inside of the vacuum chamber. Inside the vacuum chamber, there are two flat stainless steel coated with aluminum oxide at temperature ~100 °C. Since rubidium is active, I am ...
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209 views

Unusual oxidation states of alkali metals

When going through list of oxidation states on Wikipedia I encounterd there that sodium, potassium, rubidium and caesium exhibit oxidation states of -1, but not lithium, even though its ...
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84 views

Why doesn't lithium form dilithium crystals? (Calling Mr.Spock) [duplicate]

Hydrogen is in the first column of the periodic table. At STP it is a diatomic gas. When cooled and/or under pressure it forms a crystalline solid of di-hydrogen molecules. Calculations indicate that ...
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1answer
202 views

Are crown ethers “recycled”, typically?

I know that crown ethers have the interesting property of strongly complexing alkali metals, which allows them to be used in organic solvents (eg. as "dissolving-activity enhancing agents" for ...
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1answer
373 views

Does the van der Waals force not affect the alkali metal 's trend of decreasing melting points down the table? [duplicate]

Melting and boiling points increase further down the halogen group, but they decrease further down the alkali metal group. I know that the former's trend has to do with the van der Waals force, but I ...
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294 views

Does exotic potassium exist?

I was reading a book called 'Hundred and Seven Stories of Chemistry'. There is a chapter about how the attributes of different elements can change in presence of enormous pressure and temperature. ...
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1answer
18k views

Alkali metal carbonates, their thermal stability and solubility [duplicate]

From Li to Cs, thermal stability of carbonates increases. From Li to Cs, due to larger ion size, hydration enthalpy decreases. So, solubility should decrease from Li to Cs. But, experimentally, order ...