Some basic concepts of chemistry
... Elements are pure substances that cannot be decomposed into simpler substances by chemical changes. It consists of only one type of atoms. e.g. sodium (Na), silver (Ag), oxygen (O2 ), Chlorine (Cl 2 ) etc. Presently 118 different elements are known, out of which 92 are naturally occurring. Compounds ...
... Elements are pure substances that cannot be decomposed into simpler substances by chemical changes. It consists of only one type of atoms. e.g. sodium (Na), silver (Ag), oxygen (O2 ), Chlorine (Cl 2 ) etc. Presently 118 different elements are known, out of which 92 are naturally occurring. Compounds ...
Chapter 3 Stoichiometry: Ratios of Combination
... – Mole ratio (divide all moles by the smallest number of moles) – The numbers represent subscripts. • If the numbers are not whole numbers, multiply by some factor to make them whole. ...
... – Mole ratio (divide all moles by the smallest number of moles) – The numbers represent subscripts. • If the numbers are not whole numbers, multiply by some factor to make them whole. ...
Physical and Chemical Changes
... Hardness: Compare hardness of objects by seeing which one would scratch the other. ...
... Hardness: Compare hardness of objects by seeing which one would scratch the other. ...
KINETICS questions
... Describe, without doing any calculations, how graphs can be used to determine whether this reaction is first or second order in A and how these graphs are used to determine the rate constant. 1984 B For a hypothetical chemical reaction that has the stoichiometry 2 X + Y Z, the following initial ra ...
... Describe, without doing any calculations, how graphs can be used to determine whether this reaction is first or second order in A and how these graphs are used to determine the rate constant. 1984 B For a hypothetical chemical reaction that has the stoichiometry 2 X + Y Z, the following initial ra ...
General Chemistry I (FC, 09 - 10) Lab #3: The Empirical Formula of
... each crucible to 0.001 grams. Obtain pieces of tin sheet metal. (If the tin surfaces are not shiny, buff them with steel wool and wipe clean with a paper towel.) Follow the procedure below for each of your trials in this experiment. Place tin in one of the crucibles and weigh. The mass of the tin sh ...
... each crucible to 0.001 grams. Obtain pieces of tin sheet metal. (If the tin surfaces are not shiny, buff them with steel wool and wipe clean with a paper towel.) Follow the procedure below for each of your trials in this experiment. Place tin in one of the crucibles and weigh. The mass of the tin sh ...
Document
... will not oxidize since the water will. Similarly, any materials harder to reduce than water will never reduce (in water). For example, sodium ions will never reduce to sodium metal in the presence of water since the water will reduce first. In fact, sodium metal in water will spontaneously (explosiv ...
... will not oxidize since the water will. Similarly, any materials harder to reduce than water will never reduce (in water). For example, sodium ions will never reduce to sodium metal in the presence of water since the water will reduce first. In fact, sodium metal in water will spontaneously (explosiv ...
Unit 1 Mole and enthalpy changes
... You can use the relative numbers of moles of substances, as shown in balanced equations, to calculate the amounts of reactants needed or the amounts of products produced. A limiting reactant is the substance that is fully used up and thereby limits the possible extent of the reaction. Other reactant ...
... You can use the relative numbers of moles of substances, as shown in balanced equations, to calculate the amounts of reactants needed or the amounts of products produced. A limiting reactant is the substance that is fully used up and thereby limits the possible extent of the reaction. Other reactant ...
Review Ch 4 - mvhs
... Learning objective 3.1 Students can translate among macroscopic observations of change, chemical equations, and particle views. [See SP 1.5, 7.1; Essential knowledge components of 3.A–3.C] Learning objective 3.2 The student can translate an observed chemical change into a balanced chemical equation ...
... Learning objective 3.1 Students can translate among macroscopic observations of change, chemical equations, and particle views. [See SP 1.5, 7.1; Essential knowledge components of 3.A–3.C] Learning objective 3.2 The student can translate an observed chemical change into a balanced chemical equation ...
Summaries of Review Topics for AP Chemistry
... Rule # 2: Carry out mathematical operation with the units, canceling them until you end up with the unit you want in the final answer. Units are a part of all problems. If the units cancel out correctly, you know you have set up the problem correctly. A word that is used a lot with units is “per”. T ...
... Rule # 2: Carry out mathematical operation with the units, canceling them until you end up with the unit you want in the final answer. Units are a part of all problems. If the units cancel out correctly, you know you have set up the problem correctly. A word that is used a lot with units is “per”. T ...
Additional Review
... Alchemy [1500 AD] In the 1500’s many scientists were________________________________________________ ________________________________________________________________________________________ While they were not able to create gold they did discover many useful properties of matter such as: o density ...
... Alchemy [1500 AD] In the 1500’s many scientists were________________________________________________ ________________________________________________________________________________________ While they were not able to create gold they did discover many useful properties of matter such as: o density ...
Topic 16 Some non-metals and their compounds notes
... yellow non-metallic element. As an element it exits as small molecules of 8 sulfur atoms arranged in a ring. The molecule can be written as S8. ...
... yellow non-metallic element. As an element it exits as small molecules of 8 sulfur atoms arranged in a ring. The molecule can be written as S8. ...
Chapter 4 Stoichiometry Power Point
... an ionic compound made up of a cation other that H+ and an anion other that OH- or O2-: acid + base g salt + water HCl(aq) + NaOH(aq) g NaCl(aq) + H2O(l) All salts are strong electrolytes. The substance we know as table salt, NaCl, is a familiar example. However, since both the acid and the base are ...
... an ionic compound made up of a cation other that H+ and an anion other that OH- or O2-: acid + base g salt + water HCl(aq) + NaOH(aq) g NaCl(aq) + H2O(l) All salts are strong electrolytes. The substance we know as table salt, NaCl, is a familiar example. However, since both the acid and the base are ...
AS Paper 1 Practice Paper 4 - A
... The student decided to use a measuring cylinder to obtain 25.0 cm3 of the supplier’s solution. This was poured into a 250 cm3 graduated flask and the liquid level was made up to the mark with de-ionised water. The student filled a burette with the acid solution. The following results were obtained w ...
... The student decided to use a measuring cylinder to obtain 25.0 cm3 of the supplier’s solution. This was poured into a 250 cm3 graduated flask and the liquid level was made up to the mark with de-ionised water. The student filled a burette with the acid solution. The following results were obtained w ...
CHEM 250Q
... The compounds have different properties because they contain the same elements in different quantities. ...
... The compounds have different properties because they contain the same elements in different quantities. ...
Section 1 Describing Chemical Reactions Chapter 8
... CH4(g) + Al(OH)3(s) (not balanced) • Balance Al atoms Al4C3(s) + H2O(l) CH4(g) + 4Al(OH)3(s) (partially balanced) ...
... CH4(g) + Al(OH)3(s) (not balanced) • Balance Al atoms Al4C3(s) + H2O(l) CH4(g) + 4Al(OH)3(s) (partially balanced) ...
Chapter 4 - Colby College Wiki
... Balancing Redox Reactions: Half-Reactions • Write the equations for the half-reactions. – Balance all atoms except H and O (balance H and O also if they undergo redox) – Add e- based on oxidation state changes – Balance oxygen atoms using H2O – Balance hydrogen atoms using H+ • Equalize the number ...
... Balancing Redox Reactions: Half-Reactions • Write the equations for the half-reactions. – Balance all atoms except H and O (balance H and O also if they undergo redox) – Add e- based on oxidation state changes – Balance oxygen atoms using H2O – Balance hydrogen atoms using H+ • Equalize the number ...
AP Chem Summer Assignment KEY
... Practice with Nomenclature, Balancing Equations, Oxidation Numbers, Solubility Rules and Problem Solving Nomenclature: Simple Inorganic Formulas and Nomenclature – Complete Exercise 1 in the Appendix of this packet. Review the naming rules and commit the naming prefixes to memory! Oxidation Numbers: ...
... Practice with Nomenclature, Balancing Equations, Oxidation Numbers, Solubility Rules and Problem Solving Nomenclature: Simple Inorganic Formulas and Nomenclature – Complete Exercise 1 in the Appendix of this packet. Review the naming rules and commit the naming prefixes to memory! Oxidation Numbers: ...
Stoichiometry
Stoichiometry /ˌstɔɪkiˈɒmɨtri/ is the calculation of relative quantities of reactants and products in chemical reactions.Stoichiometry is founded on the law of conservation of mass where the total mass of the reactants equals the total mass of the products leading to the insight that the relations among quantities of reactants and products typically form a ratio of positive integers. This means that if the amounts of the separate reactants are known, then the amount of the product can be calculated. Conversely, if one reactant has a known quantity and the quantity of product can be empirically determined, then the amount of the other reactants can also be calculated.As seen in the image to the right, where the balanced equation is:CH4 + 2 O2 → CO2 + 2 H2O.Here, one molecule of methane reacts with two molecules of oxygen gas to yield one molecule of carbon dioxide and two molecules of water. Stoichiometry measures these quantitative relationships, and is used to determine the amount of products/reactants that are produced/needed in a given reaction. Describing the quantitative relationships among substances as they participate in chemical reactions is known as reaction stoichiometry. In the example above, reaction stoichiometry measures the relationship between the methane and oxygen as they react to form carbon dioxide and water.Because of the well known relationship of moles to atomic weights, the ratios that are arrived at by stoichiometry can be used to determine quantities by weight in a reaction described by a balanced equation. This is called composition stoichiometry.Gas stoichiometry deals with reactions involving gases, where the gases are at a known temperature, pressure, and volume and can be assumed to be ideal gases. For gases, the volume ratio is ideally the same by the ideal gas law, but the mass ratio of a single reaction has to be calculated from the molecular masses of the reactants and products. In practice, due to the existence of isotopes, molar masses are used instead when calculating the mass ratio.