What is Diluting Solutions? Subject: Chemistry Often, in analytical work, it is necessary to know how to prepare a more dilute solution from a more concentrated one. This process is called Dilution. To dilute a solution, water must be added. When…
Common units of Concentration Subject: Chemistry Chemists use grams per cubic decimetre. Remember that 1000 cubic centimetres (cm3) equals 1 cubic decimetre (dm3) also equals 1 litre (L). We note that cm3 are sometimes called millilitres (mL). E.g. if l0 g…
Define Solutions and Concentrations in terms of Chemistry Subject: Chemistry A Solution is a homogeneous mixture of two (or more) pure substances and typically consists of a solvent (the “dissolver”) which is generally present in the larger amount and a solute (the substance being dissolved)…
What is Isotopes? Subject: Chemistry Many elements have more than one type of atom. These atoms have the same number of protons but different numbers of neutrons. Atoms having different mass numbers but identical atomic numbers are called isotopes. Examples:…
Fundamental Subatomic Particles Subject: Chemistry Electrons are only found outside the nucleus. We can say that the electron has a negligible mass because it is —2000 times less heavy than both the proton and neutron. The atom is neutral therefore…
What is Atomic Structure? Subject: Chemistry An atom was once thought to be the smallest part of something that could exist. In 1897, JJ Thompson discovered that by applying high voltage to gases at low pressure, he could produce tiny, negatively…
Balancing Chemical Equations Subject: Chemistry Write the correct formula for the reactants and products; reactants on left of arrow, products on right. Choose the most complicated compound that contains the greatest number of atoms, whether it is reactant or product.…
Chemical Equation Subject: Chemistry A chemical equation is a shorthand description of the changes that occur in a chemical reaction such as Methane + Oxygen → Carbon Dioxide + Water It allows us to determine the quantitative relationships between…
Differences between Empirical Formula and Molecular Formula Subject: Chemistry Molecular formulas tell you how many atoms of each constituent are in a compound, and empirical formulas tell you the simplest or most summary ratio of elements in a compound. The molecular formula gives us…
Methods of Balancing Chemical Equations Subject: Chemistry Balancing by inspection: Consider the example: We notice that there are 2 nitrogens on both the left and right sides, so nitrogen is already balanced. There are 3 oxygens on the left but only 2…