General Chemistry

– In this subject, we will discuss the Atomic Number and Mass Number Mosley’s Determination of Atomic Number – The discovery that an atom has a nucleus that carries a positive charge raised the question: What is the magnitude of the positive charge? – This question was answered by Henry …

– In this subject, we will discuss the Rutherford’s Atomic Model (Experiment, Postulates, weakness) Alpha particles – Alpha particles are shot out from radioactive elements with very high speed. – For example, they come from radium atoms at a speed of 1.5 × 107m/sec. – Rutherford identified them to be …

– In this subject, we will discuss the Subatomic Particles: Electrons, Protons, and Neutrons Subatomic Particles – We have hitherto studied the properties of the three principal fundamental particles of the atom, namely the electron, proton, and neutron. – These are summarised in this Table:   – Nearly all of …

Cathode Rays – The discovery of electron – The knowledge about the electron was derived as a result of the study of the electric discharge in the discharge tube (J.J. Thomson, 1896). (1) The discharge tube consists of a glass tube with metal electrodes fused in the walls. (2) Through …

– In this subject, we will discuss the Kinetic Molecular Theory of Gases. Introduction to The Kinetic Molecular Theory – The gas laws help us to predict the behavior of gases, but they do not explain what happens at the molecular level to cause the changes we observe in the …

– Before you solve these problems, you can read this subject for Dalton’s Law of Partial Pressures (Statement, Mathematical, Importance, Application). – Let us understand Dalton’s law by solving these problems. Solved Problems on Dalton’s Law  Problem (1) on Dalton’s Law A mixture of oxygen and neon contains oxygen at …

– In this subject, we will discuss Dalton’s Law of Partial Pressures (Statement, Mathematical, Importance, Application). Dalton’s Law of Partial Pressures – Thus far we have concentrated on the behavior of pure gaseous substances, but experimental studies very often involve mixtures of gases. – For example, for a study of air …

– In this subject, we will discuss the Density of gas (Definition, Equation, Solved Examples) The Density of gas – From the ideal gas equation: – If we rearrange the ideal gas equation, we can calculate the density of a gas: – The number of moles of the gas, n, …

– In this subject, we will discuss the Molar Mass of gas (Definition, Equation, Solved Examples) The Molar Mass of a gas – From what we have seen so far, you may have the impression that the molar mass of a substance is found by examining its formula and summing …

– In this subject, we will discuss the Relationships between Structure and Acidity. – The strength of a Brønsted–Lowry acid depends on the extent to which a proton can be separated from it and transferred to a base. – Removing the proton involves breaking a bond to the proton, and …

– In this subject, we will discuss How to Predict the Outcome of acid-base reaction. How To Predict the Outcome of acid-base reaction – The following table gives the approximate pKa values for a range of representative compounds. – While you probably will not be expected to memorize all of the …

– In this subject, we will discuss the Orbital Representation of some Molecules (1) Orbital Representation of H2 molecule – Each hydrogen atom has one electron in 1s-orbital. – Two such atoms join to form a molecule of hydrogen. – In this case s–s overlapping between two 1s-orbitals of hydrogen …

– In this subject, we will discuss Solved Problems on The Ideal gas law  Problem (1) on The ideal gas law  Calculate the volume of a sample of gas originally occupying 908 mL at 717 torr and 20 oC after its temperature and pressure are changed to 72 oC and …

– In this subject, we will discuss the Ideal Gas Equation (Definition, Formula, Notes) The Ideal Gas Equation – Let us summarize the gas laws we have discussed so far: – We can combine all three expressions to form a single master equation for the behavior of gases: – This …

– In this subject, we will discuss the Avogadro’s Law: The Volume-Amount Relationship Avogadro’s Law: The Volume-Amount Relationship – The work of the Italian scientist Amedeo Avogadro complemented the studies of Boyle, Charles, and Gay-Lussac. – In 1811 Avogadro published a hypothesis stating that at the same temperature and pressure, …

– In this subject, we will discuss Charles’s Law: Relationship Between Temperature And Volume ( V-T relationship). Relationship Between Temperature And Volume – Boyle’s law depends on the temperature of the system remaining constant. – But suppose the temperature changes: How does a temperature change affect the volume and pressure …

– In this subject, we will discuss Boyle’s Law: Definition, Mathematical, Graphical, Applications How did Boyle discover his Law? – Robert Boyle (1627–1691) is a British chemist and natural philosopher. – Although Boyle is commonly associated with the gas law that bears his name, he made many other significant contributions …

– In this subject, we will discuss Gas Pressure: Definition, Formula, and Solved problems Gas Pressure – Gases exert pressure on any surface with which they come in contact because gas molecules are constantly in motion. – We, humans, have adapted so well physiologically to the pressure of the air …

– In this subject, we will discuss the Gaseous Substances: Substances That Exist as Gases Gaseous Substances – Under certain conditions of pressure and temperature, most substances can exist in any one of three states of matter: solid, liquid, or gas. – Water, for example, can be solid ice, liquid …

– In this subject, we will discuss the Redox Reactions: Types, Examples, Applications, Balancing. Types of Redox Reactions – Among the most common oxidation-reduction reactions are: Combination Reactions Decomposition Reactions Combustion Reactions Displacement Reactions Disproportionation Reaction (1) Combination Reactions   – A combination reaction is a reaction in which two or …