Reaction Table for Metal + Water, Steam, HCL (IMP!!!)

Potassium and Sodium

Cold Water

• reacts explosively with cold water.
• both potassium and sodium → dart around rapidly on water surface.
• potassium burns with lilac flame and sodium burns with an orange flame

Potassium: $2K(s)+2H_{2}O(l)\to 2KOH(aq)+H_2(g$

Sodium: $2Na(s)+2H_{2}O(l)\to 2NaOH(aq)+H_2(g)$

Steam Reactions are highly explosive. Should not be conducted in school laboratory

Dilute HCl

• reactions are highly explosive. should not be conducted in school laboratory

Important

Reactions are explosive → as enough heat is given out → to cause hydrogen gas to catch on fire and explode. K and Na floats on water surface as density of first 3 group I elements are less than $1g/c{m}^3$ → which is less than density of water

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Calcium

Cold Water

• reacts rapidly with cold water
• vigorous effervescence is observed.

$Ca(s)+2H_{2}O(l)\to Ca(OH{)}_2(aq)+H_2(g)$

Steam

• reaction is highly explosive and should not be conducted in school laboratory

Dilute HCl

• reacts violently with dilute HCl.

$Ca(s)+2HCl(aq)\to CaC{l}_2(aq)+H_2(g)$

Important

calcium sinks in water → density is higher than $1g/c{m}^3$ → which is density of water

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Magnesium

Cold Water

• reacts very slowly with cold water

$Mg(s)+2H_{2}O(l)\to Mg(OH{)}_2(aq)+H_2(g)$

Steam

• Hot magnesium reacts violently with steam.
• bright white glow is observed during the reaction

$Mg(s)+H_{2}O(g)\to MgO(s)+H_2(g)$

Dilute HCl

• Reacts rapidly with dilute HCl.
• vigorous effervescence is observed

$Mg(s)+2HCl(aq)\to MgC{l}_2(aq)+H_2(g)$

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Zinc

Cold Water

• no visible change → does not react with cold water

Steam

• Hot zinc reacts readily with steam
• reaction produces zinc oxide → yellow when hot and white when cool Colour of Metals and their ions in various physical states

$Zn(s)+H_{2}O(g)\to ZnO(s)+H_2(g)$

Dilute HCL

• reacts moderately fast with dilute HCl
• effervescence is observed

$Zn(s)+HCl(aq)\to ZnC{l}_2(aq)+H_2(g)$

Important

zinc is reactive metal → which reacts readily with oxygen in air → to form zinc oxide. (forms a coating over zinc)

• thus effervescence is not observed → immediately when zinc is mixed with HCl → as zinc is coated with layer of zinc oxide.
• zinc oxide (base) will react with acid first Acids + Bases (Metal oxides and Metal hydroxides)to form solution of salt and water → before zinc can react with acid to form $H_2$ gas

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Iron

Cold Water

• no visible reaction → iron does not react with cold water

Steam

• red hot iron → reacts slowly with steam → under continuous heating.

$3Fe(s)+4H_{2}O(g)\rightleftharpoons \hat{F}{e}_3{O}_4(s)+4H_2(g)$

Dilute HCl

• reacts slowly with dilute HCl
• effervescence is still observed $Fe(s)+2HCl(aq)\to FeC{l}_2(aq)+H_2(g)$

Important

\^ Fe_3O_4 is a compound which contains both $F{e}^{2+}$ and $F{e}^{3+}$ ions and is sometimes formulated as $FeO\cdot F{e}_2{O}_3$

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Lead

Cold Water, Steam, HCl

• No visible change → does not react with either of these substances

Important

• lead reacts very slowly with dilute hydrochloric acid. should react as it is more reactive than hydrogen (in the acid)
• initial reaction produces insoluble layer of $PbC{l}_2$ which coats lead and prevents lead from further reaction → with HCl.
• thus reaction stops abruptly. Does not appear to have reacted with hydrochloric acid.
• recall Salts Main Note

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Copper, Silver, Gold, Platinum

• no reaction with all 3; water, steam, HCl.

• unreactive Metals

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