Table of Contents
What is metal excess defect example?
When NaCl is heated in an atmosphere of Na vapours. The excess of Na atoms deposition in the surface of NaCl crystal Cl– ions then diffuse to the surface where the combine with Na+ ions which becomes due to losing electrons. In this defect, on heating the compound, it releases extra cations.
Which of the following will have metal excess defect?
The Correct Answer is (A) FeO. Solution: In metal deficiency defects, a cation is missing from its lattice site. This type of defect occurs in compounds where the metal can exhibit variable valency, such as the transition metal compounds.
Does NaCl have metal deficiency defect?
The correct option in the given question. In the given question FeO is the only option that shall have a metal deficiency defect.
What are the consequences of metal excess?
Paragraph :In metal excess defect, anions all missed from their lattice sites and they are occupied by electrons to maintain electrical neutrality. These sites occupied by electrons are called F-centers. Q. Q.
What is metal excess metal deficiency defect?
1) A metal excess defect is a type of crystal defect that occurs in crystal lattices. Either an anionic vacancy or an extra Cation cause these defects. Metal Deficiency Defects is a type of crystal defect that occurs in crystal lattices in which either a cation vacancy or an extra anion causes the defects.
What is metal excess and metal deficiency defect?
Is ZnO metal excess defect?
ZnO turns yellow on heating as Zn2+ ions move in interstitial sites and electrons also get entrapped in nearby interstitial sites to maintain electrical neutrality. As extra Zn2+ ions are present in interstitial sites thus, it is metal excess defect.
Does ZnS show metal deficiency defect?
Thus, ZnS shows a frenkel defect and the correct option is (b).
What is metal deficiency defect?
In metal deficiency defect, a cation is missing from its lattice site. To maintain electrical neutrality, one of the nearest metal ions acquires an extra positive charge. This type of defect occurs in compounds where the metal can exhibit variable valency. e.g., Transition metal compounds.
What are the causes of metal deficiency defect?
-Metal deficiency defect arises due to a vacant lattice site caused by missing cation. Thus one of the nearest metal ions will acquire an extra positive charge to prevent or maintain the electrical neutrality of the crystalline compound.
How many types of metal deficiency defects are there?
two types
Types of metal deficient effect These are of two types: Due to cation vacancies: A positive ion may be missing from its lattice site, and the extra negative charge balances by acquiring two positive charges instead of one. This type of defect usually occurs in compounds having a variable oxidation state.
What is metal excess defect how it occurs?
By the presence of extra cations in the interstitial sites: Metal excess defect may also cause by extra cations which occupy the interstitial sites. Electrical neutrality is maintained by an electron present in another interstitial site. This defect is found in the crystals which show Frenkel defect.
What happens to density in metal excess defect?
This defect is common when the difference in ionic radii of two participating ions is large. The presence of this defect does not alter the density of the solid. The presence of ions in interstitial sites increases the dielectric constant of the crystal.
What is metal metal deficiency excess defect?
What is metal excess defect due to extra cation?
Metal excess defect due to the presence of extra cations at interstitial sites: In this case, there are extra positive ions occupying interstitial sites and the electrons in another interstitial sites to maintain electrical neutrality.
Which type of point defect is found in sodium chloride crystal?
Schottky defects
(a) stoichiometric defect : The Schottky defects are seen in NaCl. The defects are created when the same number of Cl− and Na+ is missing from their position in the lattice and creating holes.
Does AgI show Frenkel defect?
Frenkel defects are mostly exhibited in ionic solids where the smaller ion (usually the cation) is dislocated. Some examples include AgBr, ZnS, AgCl, and AgI.
What is Scott Key defect?
Schottky defect is a type of point defect or imperfection in solids which is caused by a vacant position that is generated in a crystal lattice due to the atoms or ions moving out from the interior to the surface of the crystal.
What type of non-stoichiometric defect is shown by NaCl?
Note: Note: NaCl is actually colourless crystal. Metals excess defect is a type of non-stoichiometric defect. Non-stoichiometric defect NaCl is yellow in colour, this is one of the consequences of metal excess defect.
What are metal deficient defects?
What is the metal excess defect due to anionic vacancies?
Metal excess defect due to anionic vacancies Anionic vacancies are found in alkali halides such as NaCl and KCl. In this defect, the negative ion is missing from the lattice site leaving behind a hole which is then occupied by an electron to maintain electric balance. These electrons are trapped in the anion vacancies.
What is metal excess defect?
Metal excess defect This defect is caused due to anionic vacancies and by the presence of extra cations in the interstitial sites. When alkali metal halides are heated in an atmosphere of vapour of the alkali metal, anion vacancies are created. This anion is then diffuse to the surface of the crystal and combine with newly generated metal cations.
What happens when bleach reacts with NaOCl?
Bleach can react violently with hydrogen peroxide and produce oxygen gas: H 2 O 2 (aq) + NaOCl (aq) → NaCl (aq) + H 2 O (aq) + O 2 (g) Explosive reactions or byproducts can also occur in industrial and laboratory settings when sodium hypochlorite is mixed with diverse organic compounds.
Does NaOCl produce chlorate at 80 degrees Celsius?
The chlorate-producing reaction predominates at pH above 6, while the oxygen one becomes significant below that. For example, at 80 °C, with NaOCl and NaCl concentrations of 80 mM, and pH 6–6.5, the chlorate is produced with ∼95% efficiency.