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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Cobalt glass colour of potassium as [closed]

Given question is: Cobalt glass colour of potassium as A) Crimson red B) Lilac C) Apple green D) Brick red I thought option B as true but the given answer is option A. Because on flame test ...
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284 views

What is the colour of cesium?

I am confused with the color of cesium. Some websites and books say that it is a silvery white metal, and some say it has a golden colour, and some say it has a silvery golden colour. Among these ...
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Ease of reaction of hydrogen with alkali and alkaline earth metals

The ease of reaction of group 1 metals with hydrogen decreases as we go down the group. But why lithium requires high temperature than sodium, potassium and rubidium? What is exactly "ease of ...
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Does lithium form ionic hydride? [duplicate]

It is stated in my chemistry textbook that lithium indeed forms lithium hydrides. However, significant covalent characters could be found in lithium hydrides (like least reactivity). But in some other ...
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40 views

Metal oxide formation minimum temperature?

Is there such thing as minimum temperature for creation of metal oxide? Let's say a highly reactive metal, lithium, comes into contact with solid oxygen at a cryogenic temperature of 20 Kelvin, would ...
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85 views

Why does fcc lithium melt with increased pressure?

According to the phase diagram of lithium given here, the fcc phase formed at moderately high pressure melts at decreasing temperature upon adding more pressure, an effect better known with the ...
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53 views

Why is it that not all metals produce hydroxides when reacting with water? [duplicate]

I was taught, as a rule, that: metals + water $\rightarrow$ metal hydroxide + hydrogen gas $$\text{Na} + \text{H}_2\text{O} \rightarrow \text{NaOH} + \text{H}_2$$ However: $$3\text{Fe} + 4\text{H}...
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66 views

Lithium Oxide Colour

According to Chemistry LibreText: Lithium is the lightest of all metals and is named from the Greek work for stone (lithos). It is the first member of the Alkali Metal family. It is less dense than ...
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68 views

Can sodium metal deprotonate terminal hydrogen atom from propyne to form propynide?

I've read that sodium metal is used to form ethynides but for forming propynide, they have used $\ce{NaNH2}$. Is there some reason for not using sodium metal for propynides as well? Source: Chemistry ...
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52 views

Do positive results of a lead paint testing kit imply that a dipped door is now toxic?

We have had some 1930's doors dipped in a caustic solution to remove the paint. Before dipping, we found that a layer of yellow paint contained lead. It tested positive with: https://www.amazon.com/...
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51 views

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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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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30 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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191 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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27 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
100 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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131 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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62 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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52 views

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
145 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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93 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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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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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
932 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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611 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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171 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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271 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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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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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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149 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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126 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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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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618 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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103 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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98 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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898 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
488 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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357 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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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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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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320 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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278 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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670 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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122 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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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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339 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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314 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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198 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 ...