Question: How many moles are in 1000 g of sucrose? 1. Obtain the atomic mass First, write down the formula for sucrose: C12H22O11 2. Calculate the molar mass of sucrose To calculate the molar mass of a substance, you must Read More …
Molar mass is the weight in grams of one mole of a chemical substance. How to calculate the molar mass of a single element (eg.hydrogen)? The molar mass for an element is the sum of atomic masses, expressed as g/mol. Read More …
If moles have bank accounts, each would have:
6.02 × 10^23 amount of $$$dollars. LOL!
WHAT TYPE OF SOLID SUBLIMES? We all know that ice melts before it evaporates. In sublimation, the liquid phased is omitted.
Dissociation is the breaking down of a compound into elements and the process is usually reversible.
In 1784, a French physicist and clergyman named Jean Antoine Nollet made an interesting discovery. He filled a pig’s bladder with a concentrated solution of alcohol. He then put the bladder in water and the bladder expanded! This interesting process Read More …
Do you know that the cloudy water syndrome in a fish tank is caused by colloids? Over a period of time, organic waste produced by the fish and algae in the tank are turned into nitrates. These particles are interspersed Read More …
Irregular motion of suspended particles is called “Brownian motion”. Watch an interesting Youtube video on the discovery of Brownian Motion by British botanist Robert Brown Robert Brown was a Scottish botanist who first discovered the Brownian motion. He noticed random Read More …
Water always evaporates no matter what the temperature or atmospheric pressure is. Even in the coldest of winter, snow and ice can evaporate by a process called sublimation. They can turn straight into vapor (the gaseous stage) without melting. The Read More …
Molality is defined as the number of moles of solute per 1 (kg) of solvent. Solute = particles you dissolve Solvent = the liquid you use for dissolving the particles Example Calculate molality (m) of 29.8 g of glucose (C6H12O6) dissolved in Read More …
Freezing point depression is simply the process of LOWERING the freezing point of a liquid by adding a solute to it. Adding non-volatile substance to volatile substance lowers the temperature for freezing point.
Boiling point elevation is the elevation of a solid’s normal boiling point by adding a substance to it. When you add a solute (such as salt or sugar) to a pure solvent (such as water), the boiling point of the Read More …
Adding a solute to a pure solvent lowers the solvent’s vapor pressure. For example, water normally boils at 100ºC (212ºF) but if you add a substance like salt to the solution, it decreases the vapor pressure of the solution. First, recall Read More …
The characteristics of a solution such as the boiling point, freezing point and vapor pressure are known as colligative properties. Colligative properties apply only to solutions and not gases or solids. COLLIGATIVE PROPERTIES ARE DEPENDENT ON THE NUMBER OF ATOMS Read More …
Nonpolar molecules do not dissolve readily in water Nonpolar molecules do not become hydrated – they are repelled by water The molecules are insoluble or almost insoluble in water Oils and fats are examples of hydrophobic substances. For example, if you mix Read More …
A nonpolar covalent bond is a chemical bond where electrons are shared equally between two atoms The electrons are shared equally between the two atoms Nonpolar covalent bond electronegativity scale If the difference in electronegativity between two atoms is 0.4 Read More …
The electrons are unequally shared between two atoms When a chemical bond involves “the sharing of a pair of electrons by two atoms in a molecule”, it is generally called a covalent bond. In a polar covalent bond, the Read More …
An ionic bond An ionic bond is formed between elements of large differences in electronegativities, which are typically found between metals and non-metals. The atom that loses the electron(s) becomes a positively charged ion called a cation, and the one Read More …
A QUICK LOOK AT THE THREE DIFFERENT TYPES OF MOLECULAR BONDS HOW DO YOU FIND OUT THE TYPE OF BOND If you’re given two elements, such as carbon and oxygen, how do you tell what type of bond they will Read More …
The solubility of a substance is the amount of that substance that will dissolve in a given amount of solvent. The difference between solute and solvent SOLUTE – the substance to be dissolved SOLVENT – the liquid for dissolving the Read More …
Definition The valence electrons are the electrons in the outermost shell or last energy level of an atom. valence electrons are electrons in the last shell of an atom Valence electrons are electrons in the highest principal energy level. They Read More …
Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons.
Hello and welcome to Sufguppy. Surfguppy provides free online chemistry notes for high school and college students. If you’re a teacher or student, please feel free to use our materials for non-commercial purposes. A small portion of materials on this Read More …
In 1913 Niels Bohr proposed a model to describe how energy levels are organized around an atom. While his model is now known to be incorrect, it is useful for understanding energy levels as Bohr’s model closely resembles planets orbiting Read More …
Ionization Energy Trend Ionization energy is defined as the amount of energy needed to eject a valence electron from an atom in the gas phase. It is measured in kJ/mol. A valence electron is simply an electron located in the Read More …
Today, we are going to learn about how the periodic table is organized and the important information that it provides. Scientists discovered that if they arranged the elements according to their atomic number, properties of the elements would occur in Read More …
Photograph of Linus Pauling: Nobel Foundation, Public domain, via Wikimedia Commons The above is an example of electronegativity bond scale. It shows the different types of chemical bonds formed between atoms based on the electronegativity difference. Bond scale varies slightly Read More …
Experiments have determined that in 12 g of carbon there are 6.022 x 1023 atoms. 1 mole is defined as the number of atoms in 12 g of carbon. In other words, 1 mole of carbon contains 6.022 x 1023 Read More …
Carbon-carbon bonds A carbon atom has 4 valence electrons A single bond Most bonds that carbon form are single bonds. Single bond simply means sharing one pair of bonding electrons between two atoms and is represented by one line. Two Read More …
1 mole = 6.022 x 10^23 particles Avogadro’s Constant Molar mass = grams per 1 mole of a substance Molar mass Moles = Mass / Molar Mass Moles calculation 1 mole = number of atoms in 12 g of carbon Read More …
What is a COVALENT BOND? The term covalent bond is used to describe the bonds in compounds that result from the sharing of one or more pairs of electrons. There are two types of covalent bonds – nonpolar and polar Read More …
How to calculate molecular mass? Determine the formula of the compound Use the periodic table, determine the atomic mass of each element present in the formula Multiply the atomic mass of each element by the number of atoms Finally, add Read More …
For drawing purposes, the ring structure of the glucose molecule is broken down into three simple steps as shown below. Each molecule of glucose sugar is only 1 unit consisting of 6 carbon atoms, 12 hydrogen atoms and 6 oxygen atoms in Read More …
What are Monosaccharides? Monosaccharides are known as simple sugars, they are the simplest form of carbohydrate. They are short chain molecules containing only one chemical ring. Since they are only one ring, they can undergo chemical reactions to provide quick Read More …
Organic Chemistry Carbohydrate chemistry is a branch of organic chemistry that studies carbon compounds. Carbon can be found in food and non-food substance. As carbon plays a huge role in living things, organic chemistry is very important to medicine and life Read More …
Glucose C6H12O6 Glucose is a carbohydrate and it is one of the smallest units of sugar Its chemical formula is C6H12O6 Glucose are hexoses – 6 carbon atoms sugars In total, there are 24 atoms that form the molecule Step 1: Draw Read More …
A system refers to any parts of the universe being studied. If you are conducting an experiment in a beaker, then the system you are studying is in the beaker. The system is subject to surrounding factors such as air Read More …
What is the Octet Rule of Electron Configuration? Electron configuration is the arrangement of electrons in each energy level or shell of an atom. If the outer shell of an atom is not filled to its maximum level, the atom Read More …
Propane Combustion When 0.5 g of propane is burned, the heat produced is used to raise the temperature of 100 cm³ of water from 20ºC to 40ºC. Calculate the enthalpy change (ΔH) for the reaction. Given the density of water Read More …
Enthalpy Entropy Gibbs Free Energy Enthalpy is the amount of heat energy transferred (heat absorbed or emitted) in a chemical process under constant pressure. Entropy measures the amount of heat dispersed or transferred during a chemical process. Gibbs Read More …
The term enthalpy change is a term to describe the amount of heat that passes in or out of a system during a chemical reaction under constant pressure. Calorimeter In school, you can measure the heat exchange of a reaction Read More …
(Picture above – dog escaping over the fence – winter 2015) A spontaneous process A spontaneous process is a physical or chemical change that occurs with no outside intervention. In life, many things happen spontaneously. For example, my dog escaped Read More …
Hess’s law states that energy change in the overall chemical reaction is the sum of energy change or enthalpy change in the individual reactions that comprises it. Hess’s Law states that the heat evolved or absorbed in a chemical process is Read More …
Methane gas – CH₄ What is the enthalpy change when methane is formed using carbon graphite and hydrogen? When a chemical reaction takes place, heat is either given off or absorbed. If heat is given off, it is called an Read More …
What is Gibbs Free Energy? For a simple definition, Gibbs free energy can be described as the amount of energy available to do work. Gibbs Free Energy is invented by Josiah Willard Gibbs (February 11, 1839 – April 28, 1903) Read More …
The Haber process to manufacture ammonia using nitrogen and hydrogen is given by the equation below: Calculate Gibb’s free energy change (ΔG) at 298 K temperature. Given the entropy change (ΔS): -198 J K⁻¹ mol⁻¹ Enthalpy change (ΔH): -92 kJ Read More …
What is entropy? Entropy refers to the amount of unusable energy in a system. When water flows over a dam, it loses some of its useful energy as heat Solid wood burns to become ash and releases gases. Solid ice Read More …
We know from the periodic table that a carbon atom has 4 valence electrons in the outermost shell. In order for the atom to be more stable, the outermost shell must be filled up. Carbon follows the octet rule Read More …
Condensation polymers are any kind of polymers formed through a condensation reaction where molecules join together–losing small molecules as by-products such as water or methanol.
In addition polymerization, all the original atoms present in the monomers are retained in the polymer product.
Plastic classifications is a system established to allow consumers to properly recycle and dispose of different types of plastics. Manufactures follow a coding system and place an SPI code on each plastic product, and are usually printed or modeled into the bottom.
Polymerization is simply the process of putting together monomers (single molecules), to become a long chain of molecules (called polymers) with the use of a catalyst.
