Q2-REVIEWER-SCI PDF - Chemistry Past Paper

The quantum mechanical model of the atom primarily describe The energies and probable positions of electrons around the nucleus. the fundamental principle that states we cannot simultaneously know both the exact position and momentum of an electron- Heisenberg Uncertainty Principle According...

The quantum mechanical model of the atom primarily describe The energies and probable positions of electrons around the nucleus. the fundamental principle that states we cannot simultaneously know both the exact position and momentum of an electron- Heisenberg Uncertainty Principle According to the Quantum Mechanical Model, what describes the region of space where an electron is MOST LIKELY to be found is the ORBITAL lowest principal quantum number (n) that an electron can have IS n=1, because it represents the first energy level where electrons can exist. orbital designation has the highest energy-4s, because it fills before 3d but still has higher energy once occupied. Properties of Ionic Compounds 1. Ionic compounds are made of oppositely charged ions and are hard solid in the state. This is because they have a very strong electrostatic force of attraction between them thus, they are tightly packed and cannot be easily separated. 2. Ionic compounds have high melting and boiling points because ionic compounds are comprised of oppositely charged ions which attract each other thus, there is a strong electrostatic force of attraction between them, so a large amount of energy is needed to break the bonds and thus, they have high melting and boiling points. 3. Ionic compounds do not conduct electricity in the solid-state. This is because the electrostatic force of attraction between the ions in the solid-state is very high. Thus, there are no free mobile electrons present in the compound in solid so these compounds do not conduct electricity in solid-state. 4. Ionic compounds conduct electricity when they are infused state and are in aqueous solutions. This is because of the presence of free mobile ions in the fused state as the electrostatic force of attraction between these ions weakens infused state. On the other hand, when these compounds are dissolved into water, water being a polar covalent compound decreases the electrostatic force of attraction and thus resulting in the presence of free mobile ions in an aqueous solution. 5. Ionic compounds are highly soluble in water while they are not soluble in organic solvents like toluene. 6. Ionic compounds are good electrolytes as they can easily pass electricity through their aqueous solutions. The particles of the ionic compounds dissociate into ions and are discharged into separate particles at both the electrodes (i.e the cations get discharged at the cathode and the anions get discharged at the anode). 7. The speed of chemical equations is very fast. Since they can form ions in an aqueous solution very easily. Thus, it can form new compounds very easily. Properties of Covalent compounds 1. Covalent compounds consist of molecules and they can exist in all three states of matter (solid, liquid or gas). This is because they are made up of molecules and thus the force of attraction between these molecules are weak and so they exist in all three states of matter. 2. The melting and boiling points of covalent compounds are usually low. This is because they are made up of molecules that are held together by the weak force of attraction thus less heat is required to break the force of attraction between these molecules and so they have low melting and boiling points. 3. They are mostly non-conductor of electricity. This is because they are comprised of molecules, and, due to the absence of free mobile ions in these compounds electricity can not pass through them. 4. Non-polar covalent compounds do not ionize when dissolved into the water but polar covalent compounds. But polar covalent compounds like Hydrogen chloride, Ammonia etc. forms ions when dissolved into water and acts as electrolytes. 5. Covalent compounds do not have ions in them. Thus, they do not dissociate into ions. 6. Covalent compounds are not soluble in water but they are soluble in organic solvents like toluene. But this is the case with non-polar covalent compounds, polar covalent compounds are soluble in water. 7. The speed of reaction of covalent compounds are very slow as compared to the ionic compounds. Since covalent compounds are comprised of molecules, so in covalent compounds, old bonds are broken and new bonds are formed while forming new compounds during the chemical reactions, thus, they are slower than the ionic compounds.  -best describes the bonding capability of carbon atoms based on its electron structure IS Carbon can form up to four covalent bonds by sharing its four valence electrons. - carbon primarily form covalent bonds in organic compounds BECAUSE Carbon has four valence electrons, which allows it to share electrons with other atoms to achieve stability. - a compound containing carbon and hydrogen classified as an organic compound Because the presence of carbon- hydrogen bonds is a defining characteristic of organic compounds -describes an inorganic compound It does not contain both carbon and hydrogen together - methane considered the simplest alkane Because it contains only one carbon atom, making it the smallest possible alkane. -CH3CH2CH2CHCH2CHCH2CH3, because it is a branched alkane with eight carbon atoms. -condensed formula for octane -carbon form stable chains while other elements typically cannot Due to carbon's unique ability to form strong carbon-carbon bonds -Alkene, because it contains at least one double bond between carbon atoms -Carbon atoms can form single, double, or triple bonds." Because The ability to share multiple pairs of electrons -organic compound, any of a large class of chemical compounds in which one or more atoms of carbon are covalently linked to atoms of other elements, most commonly hydrogen, oxygen, or nitrogen -HYDROCARBON compounds with carbon and hydrogen atoms only. -ALKANE SINGLE BOND ALKENE DOUBLE BOND ALKYNE TRIPLE BOND