What happens when group 7 elements react with iron wool?
A vigorous reaction will occur and the glow will spread along the wool in the tube, producing clouds of brown iron(III) chloride. Some of this may emerge as a smoke from the end of the reduction tube.
Overview. The group 7 elements are placed on the right of the periodic table. They are called the halogens because they react with metals to form salts (from Greek hal– meaning 'salt' and –gen meaning 'to produce'). You need to know details about chlorine, bromine and iodine.
- Fluorine is the most reactive element of all in Group 7.
- You can see the trend in reactivity if you react the halogens with iron wool.
- Iron + chlorine → iron(III) chloride.
- Iron + bromine → iron(III) bromide.
- Iron + iodine → iron(III) iodide.
As you go down group 7, reactivity of the halogens decreases because: The atomic mass of the halogens increases. They increase in electron shells; so the atoms are larger as you go down the group. Therefore, the attraction of the outer electron to the nucleus decreases as you go down group 7.
The Halogens
They consist of molecules made up of two atoms (diatomic molecules). They react with metals to form ionic compounds where the halide ion has a charge of -1. They form molecular compounds with non-metals. They form hydrogen halides, which dissolve in water, forming acidic solutions.
This is because group 7 elements react by gaining an electron. As you move down the group, the amount of electron shielding increases, meaning that the electron is less attracted to the nucleus. For this reason, fluorine is the most reactive halogen and astatine is the least reactive of the halogens.
A vigorous reaction will occur and the glow will spread along the wool in the tube, producing clouds of brown iron(III) chloride. Some of this may emerge as a smoke from the end of the reduction tube.
Burning Steel Wool is a Chemical Reaction
But the strands of steel wool are thin enough with enough surface area that the heat produced is self-sustaining and will continue to burn through if there is enough air present.
The order of reactivity is chlorine > bromine > iodine. This is because chlorine could displace bromine and iodine, bromine could only displace iodine, but iodine could not displace chlorine or bromine.
Iron enters into a reaction with substances of different classes, and interacts with oxygen, carbon, phosphorus, halogens (bromine, iodine, fluorine and chlorine), and also nitrogen.
What is the reactivity series Group 7?
The reactivity of Group 7 elements decreases down the group. Non-metal atoms gain electrons when they react with metals. When a halogen atom reacts, it gains one electron into their highest occupied energy level (outer shell) to form a singly negative charged ion.
As you move down group 7, the atomic radius get bigger (more protons, more electrons, more shells) and so the negatively charged electrons in the outer shell move further away from the positively charged nucleus. This means that the attraction between the two is weaker.
Why do halogens get more reactive going upwards in group 7? Halogens from bromide to fluorine get more reactive because the force of attraction between the nucleus (core) and the outer electron get stronger as you go up group 7 elements.
When reacting with metals, halogens form salts with a giant ionic structure, and when reacting with hydrogen, they form hydrogen halides.
When halogens react with non-metals, they form molecules. For example, when chlorine reacts with hydrogen, it forms hydrogen chloride. These compounds are often polar, meaning they have a positive and negative end, and can dissolve in water to form acids.
They dissolve in water to produce acidic solutions . Hydrogen chloride dissolves in water to produce hydrochloric acid, HCl(aq).
Group 7 contains non-metal elements placed in a vertical column on the right of the periodic table. The elements in group 7 are called the halogens . The halogens show trends in their physical and chemical properties .
The reactivities of the halogens(17th group) decrease down the group ( At < I < Br < Cl < F). This is due to the fact that atomic radius increases in size with an increase of electronic energy levels. This lessens the attraction for valence electrons of other atoms, decreasing reactivity.
Halogens are highly reactive because they readily gain an electron to fill their outermost shell. Alkali metals are highly reactive because they readily lose the single electron in their outermost shell.
The melting points and boiling points of the halogens increase going down group 7. This is because, going down group 7: the molecules become larger. the intermolecular forces become stronger.
What happens when iron wool is heated?
When iron wool combusts, it reacts with oxygen from the air to form iron oxide. Iron oxide is a solid, so the oxygen atoms from the air add to the mass on the balance. The balance tips as the iron wool reacts with the oxygen to form solid iron oxide.
They have high ionization energies and form the most electronegative group of elements. Their electron configuration, ns2np5, allows them to easily react with Group 1 and 2 metals; each halogen tends to pick up one electron, and the Group 1 and Group 2 elements each tend to lose one or two electrons, respectively.
Heated iron wool (Fe) produces flames as it reacts with chlorine gas (Cl2) in a flask, forming fumes of iron (III) chloride (FeCl3) which is a yellow-brown solid.
But why does steel wool burn? Iron is actually a flammable substance. Steel wool, which is primarily iron, has a very high surface area that exposes it to oxygen. Combine that with the thin fibers that quickly transmit heat and you can maintain combustion.
Live Science interviews UB chemist Jason Benedict in a story titled, “Here's How Steel Wool Burns (and Why It Looks Like the Death of Krypton).” The story explains that steel wool burns because it has lots of thin strands holding atoms that come into contact with oxygen in the air, making it more difficult for heat to ...
Iron wool heated to glowing red reacts vigorously with chlorine gas in a flask. The product is red-brown solid iron(III) chloride. Evidence for this product is the fact that when it is dissolved in water a yellow-orange solution results. This is characteristic of iron(III) ions in aqueous solution.
Washing the fabric with an alkaline material that has a pH much above 8 (a neutral pH is 7) can harm wool and silk because they are acidic materials. Avoid borax, washing soda, or ammonia; these are alkaline materials, as are some soaps.
| Linear Formula | Fe |
|---|---|
| EC No. | 231-096-4 |
| Beilstein/Reaxys No. | N/A |
| Pubchem CID | 23925 |
| SMILES | [Fe] |
Steel wool (iron) will burn in air quite gently, since air is about 20% (by volume) oxygen. When the steel wool is placed in 100% oxygen the reaction proceeds much faster and vigorously.
Among the halogens, fluorine is the most reactive. Group seven's most reactive element, fluorine, is significantly more reactive than chlorine.
What are the chemical trends in group 7?
In group 7, the further down the group an element is, the higher its melting point and boiling point . This is because, going down group 7: the molecules become larger. the intermolecular forces become stronger.
Lr. Group 7A (or VIIA) of the periodic table are the halogens: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At).
Three things must be present for rusting to occur: iron, oxygen, and water. Rust forms when these three elements combine and create an electrochemical reaction. iron + water + oxygen → hydrated iron(III) oxide.
In dry air, iron remains inactive and does not react (with air); however, in moist air, it reacts and forms rust. Pure iron normally does not react with pure water; however, it reacts easily with ordinary of polluted water and rust forms.
- Fe(OH)2 ⇌ FeO + H2O.
- 4Fe(OH)2 + O2 + xH2O → 2Fe2O3.(x+4)H2O.
- Fe(OH)3 ⇌ FeO(OH) + H2O.
- 2FeO(OH) ⇌ Fe2O3 + H2O.
Non-metals in group 7 – the non-metals of group 7 need to gain one electron, so become ions with a -1 charge.
The reactivity of Group 7 elements decreases down the group. Non-metal atoms gain electrons when they react with metals. When a halogen atom reacts, it gains one electron into their highest occupied energy level (outer shell) to form a singly negative charged ion.
When the alkali metals react with the different halogens (Group 7 of the periodic table), the group of compounds formed are known as the alkali metals halides.
When halogens react with metals, they form salts, also known as halides. The halide ion will have a negative charge and the metal ion will have a positive charge.
A vigorous reaction will occur and the glow will spread along the wool in the tube, producing clouds of brown iron(III) chloride. Some of this may emerge as a smoke from the end of the reduction tube.
What happens when chlorine reacts with iron wool?
Iron wool heated to glowing red reacts vigorously with chlorine gas in a flask. The product is red-brown solid iron(III) chloride. Evidence for this product is the fact that when it is dissolved in water a yellow-orange solution results. This is characteristic of iron(III) ions in aqueous solution.
Heated iron wool (Fe) produces flames as it reacts with chlorine gas (Cl2) in a flask, forming fumes of iron (III) chloride (FeCl3) which is a yellow-brown solid. The equation for this reaction is: 2 Fe + 3 Cl2 ---> 2 FeCl3.
So, when reacting with metals, halogens gain an electron to complete their outer shell and form a negative ion, while metals lose an electron to become a positive ion. The positive and negative ions then attract each other and form an ionic bond, resulting in the formation of an ionic compound.
When a Group 7 element reacts, it gains one electron to form a negative ion with a stable electronic configuration – a full outer shell. As we move down the column of Group 7 elements, their reactivity decreases.
Reactions with hydrogen
They dissolve in water to produce acidic solutions . Hydrogen chloride dissolves in water to produce hydrochloric acid, HCl(aq).
As you move down group 7, the atomic radius get bigger (more protons, more electrons, more shells) and so the negatively charged electrons in the outer shell move further away from the positively charged nucleus. This means that the attraction between the two is weaker.
Alkali metals have very low ionization energy, readily losing an electron, while halogens have very high electronegativity, readily gaining an electron. This interaction allows the alkali metals to form ionic bonds with the halogens.
Explaining reactivity [Higher tier only]
As we descend Group 7, the reactivity decreases. For stability, the atom needs to have a full outer shell. Group 7 elements need to gain 1 electron to have a full shell.
The group 7 elements want to gain one more electron so that they have a stable electronic structure. The smaller the atom, the easier it is to grab an electron from another atom, making the atom more reactive.
Group 7 elements however have 7 electrons in their outermost shells, so they react by gaining an electron to form an outermost ring of 8 electrons.