# 18.5 Occurrence, preparation, and compounds of hydrogen  (Page 3/9)

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Chemical Reactions of Hydrogen with Other Elements
${\text{MH or MH}}_{2}\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}\text{MOH or M}{\left(\text{OH}\right)}_{2}+{\text{H}}_{2}$ ionic hydrides with group 1 and Ca, Sr, and Ba
${\text{H}}_{2}+\text{C}\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}\text{(no reaction)}$
${\text{3H}}_{2}+{\text{N}}_{2}\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}{\text{2NH}}_{3}$ requires high pressure and temperature; low yield
${\text{2H}}_{2}+{\text{O}}_{2}\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}{\text{2H}}_{2}\text{O}$ exothermic and potentially explosive
${\text{H}}_{2}+\text{S}\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}{\text{H}}_{2}\text{S}$ requires heating; low yield
${\text{H}}_{2}+{\text{X}}_{2}\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}\text{2HX}$ X = F, Cl, Br, and I; explosive with F 2 ; low yield with I 2

## Reaction with compounds

Hydrogen reduces the heated oxides of many metals, with the formation of the metal and water vapor. For example, passing hydrogen over heated CuO forms copper and water.

Hydrogen may also reduce the metal ions in some metal oxides to lower oxidation states:

${\text{H}}_{2}\left(g\right)\phantom{\rule{0.2em}{0ex}}+\phantom{\rule{0.2em}{0ex}}{\text{MnO}}_{2}\left(s\right)\phantom{\rule{0.2em}{0ex}}\stackrel{\phantom{\rule{0.4em}{0ex}}\text{Δ}\phantom{\rule{0.4em}{0ex}}}{\to }\phantom{\rule{0.2em}{0ex}}\text{MnO}\left(s\right)+{\text{H}}_{2}\text{O}\left(g\right)$

## Hydrogen compounds

Other than the noble gases, each of the nonmetals forms compounds with hydrogen. For brevity, we will discuss only a few hydrogen compounds of the nonmetals here.

## Nitrogen hydrogen compounds

Ammonia, NH 3 , forms naturally when any nitrogen-containing organic material decomposes in the absence of air. The laboratory preparation of ammonia is by the reaction of an ammonium salt with a strong base such as sodium hydroxide. The acid-base reaction with the weakly acidic ammonium ion gives ammonia, illustrated in [link] . Ammonia also forms when ionic nitrides react with water. The nitride ion is a much stronger base than the hydroxide ion:

${\text{Mg}}_{3}{\text{N}}_{2}\left(s\right)\phantom{\rule{0.2em}{0ex}}+\phantom{\rule{0.2em}{0ex}}{\text{6H}}_{2}\text{O}\left(l\right)\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}\text{3Mg}{\left(\text{OH}\right)}_{2}\left(s\right)+{\text{2NH}}_{3}\left(g\right)$

The commercial production of ammonia is by the direct combination of the elements in the Haber process    :

${\text{N}}_{2}\left(g\right)+{\text{3H}}_{2}\left(g\right)\stackrel{\phantom{\rule{0.2em}{0ex}}\text{catalyst}\phantom{\rule{0.2em}{0ex}}}{\text{⇌}}{\text{2NH}}_{3}\left(g\right)\phantom{\rule{5em}{0ex}}\text{Δ}H\text{°}=\text{−92 kJ}$

Ammonia is a colorless gas with a sharp, pungent odor. Smelling salts utilize this powerful odor. Gaseous ammonia readily liquefies to give a colorless liquid that boils at −33 °C. Due to intermolecular hydrogen bonding, the enthalpy of vaporization of liquid ammonia is higher than that of any other liquid except water, so ammonia is useful as a refrigerant. Ammonia is quite soluble in water (658 L at STP dissolves in 1 L H 2 O).

The chemical properties of ammonia are as follows:

1. Ammonia acts as a Brønsted base, as discussed in the chapter on acid-base chemistry. The ammonium ion is similar in size to the potassium ion; compounds of the two ions exhibit many similarities in their structures and solubilities.
2. Ammonia can display acidic behavior, although it is a much weaker acid than water. Like other acids, ammonia reacts with metals, although it is so weak that high temperatures are necessary. Hydrogen and (depending on the stoichiometry) amides (salts of ${\text{NH}}_{2}{}^{\text{−}}\right),$ imides (salts of NH 2− ), or nitrides (salts of N 3− ) form.
3. The nitrogen atom in ammonia has its lowest possible oxidation state (3−) and thus is not susceptible to reduction. However, it can be oxidized. Ammonia burns in air, giving NO and water. Hot ammonia and the ammonium ion are active reducing agents. Of particular interest are the oxidations of ammonium ion by nitrite ion, ${\text{NO}}_{2}{}^{\text{−}},$ to yield pure nitrogen and by nitrate ion to yield nitrous oxide, N 2 O.
4. There are a number of compounds that we can consider derivatives of ammonia through the replacement of one or more hydrogen atoms with some other atom or group of atoms. Inorganic derivations include chloramine, NH 2 Cl, and hydrazine, N 2 H 4 :

what is electricity
electricity refers to the flow electrons
John
Hi. please can you tell me more on chemical equation
When 1 or 2 chemicals react, they rearrange their atomic composition forming new compounds. The total mass before and after is the same/ constant. Chemical equations of same reactants react in same ratios e.g. 1 Na ion reacts with 1 water molecule or a multipier like 1 mole of Na ions react with 1
Abdelkarim
Mole of water molecules. In that example we multipied by 6.02*10^23 or avogadro constant (L). Or 2 Na+ ions with two water molecules. The arrow means '' to form '' Some times conditions or reactants are written above the arrow like H+ or enzyme or temper, sometimes physical states are written
Abdelkarim
Beside the chemical Aqueous (aq) which means solute dissolved on water. Solid (s) etc Some chemical equations are written next to it ΔH= # which means enthalpy change which describes if the reaction is endothermic (+) or exothermic (-).
Abdelkarim
Some are reversible and have half double arrow sign.
Abdelkarim
what is the meaning of atoma
what is theory
what is chemical compound
Lorrita
A compound is the result of chemical bonding between 2 or more different elements.
Abdelkarim
difference between Amine and amide
what is the difference between alkanal and alkanone
difference between alkanol and alkanal
Michael
whaatt
Saturday
you are not well at all
Ibrahim
is organic compounds used for drying agent
Sulfuric acid is used as a drying agent.
Abdelkarim
what is an atom
An atom is the smallest part of an element, for instance gold atoms are the smallest part of gold that can enter a reaction. An atom must consist protons and electrons of equal number. You can think of those subatomic particles as spheres, but not orbiting randomly they move in specific way in
Abdelkarim
That was partially described mathematically. As a muslim, we believe that god created all matter from nothing. He is the Able, and only who can create matter in the begging in the big bang that was described in the Quran in chapter 17 verse 30, 1400 years ago, you can read it from internet.
Abdelkarim
what is electron affinity
John
do you have a private jet
Ibrahim
what is acid
Proton donor (H+). Like in lemons, oranges and some medicines.
Abdelkarim
what is titration? and how can i get my readings?
what is electrolysis?
what is the formula you use when calculating for gas law?
favor
PV=nrt
Farid
electro-means electricity while lysis-means splitting up so electrolysis simply means splitting up by means of electric current
John
good day. how may I see previous question asked in this chat, please?
Asha
Asha, A person named Favor asked what is meant by the term electrolysis
John
what is a sample
According to google, a speciemen taken for specific testing or analysis.
Abdelkarim
how would you carry out a qualitative analysis for two samples of salt suspected to contain chloride ion, bromide ion,iodide ion and carbonate ion
You can search google for test for these ions or test for anions ingeneral which will help you as it contauns videos too.
Abdelkarim
what is acid
Olubodun
why don't you just search for what is acid
Ibrahim
This is a question you're being tested Abdelkarim stop being rude
John
an element x with electronic configurations as 2s²,2p²,3p6,combines with another element y with electronic configuration as 1s², 2p²,3p²,3p5,derive the chemical formula of the compound
These electrongic configuration are entered wrong, any way, you can use an app called peridoic table 2021 that has advabced electric configuration in your studying. Use it to learn about patterns easier. And use it to solve problem: identify elements, then figure out bonding and ration for example:
Abdelkarim
The elemtents are H and S Then the formula is H2S.
Abdelkarim
an element x with electronic configurations as 2s²,2p²,3p6,combines with another element y with electronic configuration as 1s², 2p²,3p²,3p5,derive the chemical formula of the compound
what is atomic number
Dorcas
It is the number of protons in the nucleus of an atom, which is unique for each element e.g only gold atoms have 79 protons in their nucleus.
Abdelkarim
hmm
favor
the number present in proton in nucleus of an atom
favor