Explanation

• Stoichiometry is a term derived from the Greek words "stoicheion" (element) and "metron" (measure).
• It refers to the study of the quantitative relationships between reactants and products in chemical reactions, and is a fundamental concept in chemistry.

Explanation

• The new classification of acid and base, based on the description of the proton, was given by Johannes Brønsted and Thomas Lowry.
• They defined an acid as a compound that donates a proton (H+) and a base as a compound that accepts a proton.
• This definition is broader than the Arrhenius definition, which is limited to aqueous solutions, and it has been widely accepted and used in chemistry.

Explanation

The Boltzmann distribution is a probability distribution that describes how the energy of a system is distributed among its possible states. It is commonly used to describe the behavior of ideal gases, and is given by the equation: f(E) = (1/Z) * e^(-E/kT)

where:

• f(E) is the probability of finding the system in a state with energy Z is the partition function, which is a normalization constant
• E is the energy of the state
• k is Boltzmann's constant
• T is the temperature of the system.

Explanation

• Phenylamine (aniline) is a crucial starting material for the production of many dyes, including acid dyes, basic dyes, and direct dyes.
• These dyes are used to color a wide range of materials, such as fabrics, leather, and paper.

Explanation

Amines are of three types, primary, secondary and tertiory.

1. Primary amines are those which directlr attached to one carbon as CH3NH2 or RNH2.
2. Secondary amines are those which attached to two more carbon atoms as C2H5 − NH − C2H5 or R2NH
3. Tertiory amines all valency of nitrogen are satisfied by alkyl groupe R3N.

Explanation

Chemistry is the scientific study of the composition, properties, and reactions of matter. It deals with the analysis, synthesis, and transformation of matter, and explores the relationships between the properties of matter and its composition.

Chemistry is concerned with:

• Composition: The types and amounts of elements present in a substance.
• Properties: The characteristics of a substance, such as its color, melting point, boiling point, reactivity, and solubility.

Explanation

The d-block elements are located in the periodic table between the s-block and p-block elements and are characterized by the filling of the d subshell. These elements are known as transition elements or transition metals.

Explanation

• An oxidation number (also known as oxidation state) is a number assigned to an atom or ion in a compound that represents its degree of oxidation, or its hypothetical charge if all its bonds were ionic.
• It is a way to keep track of the number of electrons gained or lost by an atom in a chemical reaction.

Explanation

• When equal masses of methane (CH4) and oxygen (O2) are mixed, the number of moles of each gas is equal. Since the molar mass of methane (16 g/mol) is smaller than that of oxygen (32 g/mol), the number of molecules of methane is greater than the number of molecules of oxygen.
• Let's calculate the fraction of total pressure exerted by oxygen:
• Number of moles of methane = Number of moles of oxygen (since equal masses are mixed)
• Molar ratio of methane to oxygen = 1:1
• Total pressure = Partial pressure of methane + Partial pressure of oxygen = 1 (due to methane) + 1 (due to oxygen) = 2
• Fraction of total pressure exerted by oxygen = Partial pressure of oxygen / Total pressure = 1 / 2 = 2/3

Explanation

• Atoms having same atomic number but different atomic mass, are known as isotopes.
• The difference in the mass is due to the difference in their number of neutrons with the same number of electrons and protons.