Complete the following reactions:(i) \$H_2\, (g)\, +\, M_{m}O_o\, (s)\, \overset{\Delta}{\rightarrow}\$(ii) \$CO\, (g)\, +\, H_2\, (g)\, \xrightarrow[catalyst]{\Delta }\$(iii) \$C_3H_8\, (g)\, +\, 3H_2O\, (g)\, \xrightarrow[catalyst]{\Delta }\$(iv) \$C_3H_8\, (g)\, +\, 3H_2O\, (g)\, \xrightarrow[catalyst]{\Delta }\$

The complete reaction is as follows:\$\displaystyle oH_2\, (g)\, +\, M_{m}O_o\, (s)\, \overset{\Delta}{\rightarrow} mM(s) + oH_2O(l) \$\$\displaystyle CO\, (g)\, +\, H_2\, (g)\, \xrightarrow[\text { catalyst}]{\Delta } \underset {\text { methanol}}{CH_3OH(l)} \$\$\displaystyle C_3H_8\, (g)\, +\, 3H_2O\, (g)\, \xrightarrow[\text { catalyst}]{\Delta } 3CO(g)+7H_2(g) \$\$\displaystyle Zn\, (s)\, +\, NaOH\, (aq)\, \xrightarrow[]{\text { heat}} \underset {\text { Sodium zincate}}{Na_2ZnO_2(aq)} + H_2(g) \$

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>>Class 11
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>> $Preparation, Properties and Uses of Dihydrogen$

Preparation, Properties and Uses of Dihydrogen

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Q: The drain cleaner, Drainex contains small bits of aluminum which react with caustic soda to produce dihydrogen. What volume of dihydrogen at \$20^o C\$ and one bar will be released when 0.15 g of aluminum reacts?

The reaction can be written as:-\$2Al_{(s)}+2NaOH_{(aq)}+2H_2O_{(l)}\longrightarrow {2NaAlO_2}_{(aq)}+{3H_2}_{(g)}\$Here, \$2\$ moles of \$Al\$ gives \$3\$ moles of \$H_2\$ gas.Moles of aluminium= \$\cfrac {0.15g}{27}=5.56\times 10^{-3}\$ moles\$\therefore\$ Moles of \$H_2\$ produced= \$\cfrac {3}{2}\times 5.56\times 10^{-3}\$=\$8.33\times 10^{-3}\$ moles\$\therefore\$ Volume of \$H_2\$=\$\cfrac {nRT}{P}\$=\$\cfrac {8.33\times 10^{-3}\times 0.0831\times 293}{1}\$=\$0.203\$ litres\$\therefore\$ Volume of dihydrogen released is \$0.203\$ litres

Q: Which of the following has the most acidic hydrogen?1) 3- Hexanone 2) 2,4- Hexanedione3) 2,5- Hexanedione 4) 2,3- Hexanedione

The correct option is 22,4 Hexanedione has most acidic hydrogen this is because the Carbanion left after the removal of \$H^+\$ is resonance.

Q: In which of the following reactions does hydrogen act as an oxidising agent:

Reaction:\$2{ Na }+{ H }_{ 2 }\longrightarrow 2NaH\$0 +1here, it oxidises Na so it acts as oxidising agent.

Q: What happens when dil. hydrochloric acid is added to iron filings?

When dilute Hydrochloric acid is added to iron filings, iron chloride & hydrogen gas is produced.\$Fe+2HCl\longrightarrow FeCl_2+H_2\$The iron displaces hydrogen from hydrochloric acid to form iron (II) chloride & hydrogen gas. This is a single displacement reaction.Thus the answer is option (A) Hydrogen gas and iron chloride are produced.

Q: Out of the following metals which will give \$H_2\$ reaction with \$NaOH\$?\$I: Zn\$\$II: Mg\$\$III: Al\$\$IV: Be\$

The reactions of following metals with \$NaOH\$ can be given as:-\$Zn+2NaOH\longrightarrow Na_2ZnO_2+H_2\$\$Mg+2NaOH\longrightarrow 2Na+Mg(OH)_2\$\$2Al+2NaOH+2H_2O\longrightarrow 2NaAlO_2+3H_2\$\$Be+NaOH+H_2O\longrightarrow Na_2[Be(OH)_4]+H_2\$From the above reactions, it is clear that \$Zn,Al\$ and \$Be\$ react with \$NaOH\$ to give \$H_2\$ while \$Mg\$ does not.

Q: Which of the following metals does not liberate hydrogen from acids?

Copper, silver, gold and platinum being less reactive than hydrogen cannot displace hydrogen from acids. Metals that are more reactive than hydrogen can displace hydrogen from acids. These metals include sodium, potassium, lead and zinc.

Q: When the same amount of zinc is treated separately with excess of sulphuric acid and excess of sodium hydroxide, the ratio of volumes of hydrogen evolved is__________.

The reactions of zinc with sulphuric acid and excess of sodium hydroxide separately are given below:\$\displaystyle Zn + 2NaOH \rightarrow Na_{2}ZnO_{2} + H_{2}\$\$Zn + H_{2}SO_{4} \rightarrow ZnSO_{4} + H_{2}\$In both the reactions, \$1\$ mole of \$H_2\$ is evolved.Hence, the ratio of volumes of hydrogen evolved is \$1:1\$.

Q: Which of the following will not produce hydrogen gas?

\$(A)\$ Iron reacts with dil. \$HCl\$ to produce ferrous chloride and hydrogen.\$Fe+2HCl \rightarrow FeCl_2 + H_2\$\$(B)\$ Zinc reacts with dil sulphuric acid to produce zinc sulphate and hydrogen (lab method).\$Zn +\$ dil. \$H_2SO_4 \rightarrow ZnSO_4 + H_2\$. However conc. sulphuric acid cannot be used because \$SO_2\$ and \$H_2O\$ is evolved. \$H_2SO_4 + H_2 \rightarrow 2H_2O + SO_2 \$\$(C)\$ Zinc reacts with \$NaOH\$ to form sodium zincate and hydrogen.\$Zn+2NaOH \rightarrow \underset {\text {sodium zincate}}{Na_2ZnO_2} +H_2\$\$(D)\$ During the electrolysis of aqueous \$NaCl\$ in Nelson's cell, hydrogen gas is obtained. Water dissociates to small extent, \$H_2O \rightleftharpoons H^+ + OH^-\$.Hydrogen ions are reduced to hydrogen.\$2H^+ +2e^- \rightarrow H_2\$.

Q: What is the difference between \$2H\$ or \$H_{2}\$.

\$\textbf{Explanation :}\$ \$H_2\$ is a molecule. When two atoms of hydrogen combine together with a single bond, they form molecular hydrogen.But, \$2H\$ is actually two atoms of hydrogen in elemental form. These two hydrogen atoms are not bonded with each other through any kind of bond.\$\textbf{Additional information :}\$ Hydrogen is the lightest element with atomic number \$1 AMU\$. Molecular hydrogen is a colorless, odorless, tasteless, and highly flammable gas.

Commercial production of dihydrogen

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Preparation and Properties of Dihydrogen

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Chemical Properties of Dihydrogen

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Uses of Dihydrogen

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Preparation of Hydrogen

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What is the difference between $2 H$ or $H_{2}$ .

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Dihydrogen - Preparation and Physical Properties

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Preparation of Hydrogen

Properties of Dihydrogen

Uses of Dihydrogen

The drain cleaner, Drainex contains small bits of aluminum which react with caustic soda to produce dihydrogen. What volume of dihydrogen at 20oC and one bar will be released when 0.15 g of aluminum reacts?

Which of the following has the most acidic hydrogen? 1) 3- Hexanone 2) 2,4- Hexanedione 3) 2,5- Hexanedione 4) 2,3- Hexanedione

Complete the following reactions: (i) H2​(g)+Mm​Oo​(s)→Δ (ii) CO(g)+H2​(g)Δcatalyst​ (iii) C3​H8​(g)+3H2​O(g)Δcatalyst​ (iv) C3​H8​(g)+3H2​O(g)Δcatalyst​

In which of the following reactions does hydrogen act as an oxidising agent:

What happens when dil. hydrochloric acid is added to iron filings?

Out of the following metals which will give H2​ reaction with NaOH? I:Zn II:Mg III:Al IV:Be

Which of the following metals does not liberate hydrogen from acids?

When the same amount of zinc is treated separately with excess of sulphuric acid and excess of sodium hydroxide, the ratio of volumes of hydrogen evolved is__________.

Which of the following will not produce hydrogen gas?

What is the difference between 2H or H2​.

The drain cleaner, Drainex contains small bits of aluminum which react with caustic soda to produce dihydrogen. What volume of dihydrogen at $2 0^{o} C$ and one bar will be released when 0.15 g of aluminum reacts?

Which of the following has the most acidic hydrogen?
1) 3- Hexanone 2) 2,4- Hexanedione
3) 2,5- Hexanedione 4) 2,3- Hexanedione

Complete the following reactions:

(i) $H_{2} (g) + M_{m} O_{o} (s) \to Δ$
(ii) $C O (g) + H_{2} (g) Δ c a t a l y s t$
(iii) $C_{3} H_{8} (g) + 3 H_{2} O (g) Δ c a t a l y s t$
(iv) $C_{3} H_{8} (g) + 3 H_{2} O (g) Δ c a t a l y s t$

Out of the following metals which will give $H_{2}$ reaction with $N a O H$ ?
$I : Z n$
$I I : M g$
$I I I : A l$
$I V : B e$

What is the difference between $2 H$ or $H_{2}$ .