Metal deficiency defect is shown by \(Fe_{0.93}O\). In the crystal, some \(Fe^{2+}\) cations are missing and loss of positive charge is compensated by the presence of \(Fe^{3+}\) ions. The percentage of \(Fe^{2+}\) ions in the \(Fe_{0.93}O\) crystals is ______ . (Nearest integer)
Correct Answer: 85
Solution and Explanation
Let the number of \(O^{–2}\) ions be \(100\)
and the number of \(Fe^{+2}\) ions be \(X\)
The number of \(Fe^{+3}\) ions be \((93 – X)\)
\(∴ X(2) + (93 – X)3 = 200\)
\(279 – X = 200\)
\(X = 279-200\)
\(X = 79\)
∴ % of \(Fe^{+2}\) ions\(=\frac {79}{93}×100\)
≃ 85%
So, the answer is 85%.
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Concepts Used:
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Chemistry is a vast subject and for understanding its significance we can take help of following points:
- Chemistry plays an important role in understanding various subjects like physics, geology and biology.
- Chemistry is a core branch of science that explains us about the various compositional properties and interaction of matter. It also helps to understand various chemical reactions.
- Chemistry is important in order to understand the behaviour of fertilizers, alkenes, acids, salts, dyes, polymers, drugs, soaps and alloys in organic and inorganic chemistry.
- Chemistry plays an important role in various fields like healthcare, industrial, research, food, and farm activities.
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Classification of Matter
There are two ways of classifying the matter:
(A) Physical Classification:
Matter can exist in three physical states:
- Solids - have definite volume and definite shape
- Liquids - have definite volume but not definite shape.
- Gases - have neither definite volume nor definite shape.
(B) Chemical Classification:
Based upon the composition, matter can be divided into two main types:
- Pure Substances are defined as a single substance (or matter) which cannot be separated by simple physical methods. Pure substances can be further classified as (i) Elements (ii) Compounds
- Mixtures are the combination of two or more elements or compounds which are not chemically combined together and may also be present in any proportion.