2.4 Chemical equilibria
... reaction in a closed system. Nothing can be added to the system or taken away from it apart from energy. At equilibrium, the quantities of everything present in the mixture remain constant, although the reactions are still continuing. This is because the rates of the forward and the back reactions a ...
... reaction in a closed system. Nothing can be added to the system or taken away from it apart from energy. At equilibrium, the quantities of everything present in the mixture remain constant, although the reactions are still continuing. This is because the rates of the forward and the back reactions a ...
5. Formulae, equations and amounts of substance
... Using a gas syringe Gas syringes can be used for a variety of experiments where the volume of a gas is measured, possibly to work out moles of gas or to follow reaction rates. The volume of a gas depends on pressure and temperature so when recording volume it is important to note down the temperatur ...
... Using a gas syringe Gas syringes can be used for a variety of experiments where the volume of a gas is measured, possibly to work out moles of gas or to follow reaction rates. The volume of a gas depends on pressure and temperature so when recording volume it is important to note down the temperatur ...
Chemical Reactions - Johnston County Schools
... •The magnesium atom (which has zero charge) changes to a magnesium ion by losing 2 electrons, and is oxidized to Mg2+ •The sulfur atom (which has no charge) is changed to a sulfide ion by gaining 2 electrons, and is reduced to S2- ...
... •The magnesium atom (which has zero charge) changes to a magnesium ion by losing 2 electrons, and is oxidized to Mg2+ •The sulfur atom (which has no charge) is changed to a sulfide ion by gaining 2 electrons, and is reduced to S2- ...
Covalent Bonds - WordPress.com
... The Energy Levels of Electrons • Electrons of atoms participate in reactions • Energy is the capacity to cause change • Potential energy is the energy that matter has because of its location or structure • The electrons of an atom differ in their amounts of potential energy • An electron’s state of ...
... The Energy Levels of Electrons • Electrons of atoms participate in reactions • Energy is the capacity to cause change • Potential energy is the energy that matter has because of its location or structure • The electrons of an atom differ in their amounts of potential energy • An electron’s state of ...
Midterm Review 4
... a. 36.0 g b. 22.0 g c. 44.0 g d. 6.02 x 1023 g 45. The sum of the atomic masses of all the atoms in a compound is called the ___. a. molar mass b. empirical formula c. molar volume d. percentage composition 46. The number of atoms in one mole of an element is equal to___. a. a measure b. a gram c. a ...
... a. 36.0 g b. 22.0 g c. 44.0 g d. 6.02 x 1023 g 45. The sum of the atomic masses of all the atoms in a compound is called the ___. a. molar mass b. empirical formula c. molar volume d. percentage composition 46. The number of atoms in one mole of an element is equal to___. a. a measure b. a gram c. a ...
New AQA C3 revison guide
... In most jugs the cartridge needs to be changed every few weeks. Even water that has been treated and passed through a filter jug is not pure. It will still contain many dissolved substances. But despite this it is safe to drink. We can get totally pure water by distilling(boiled then condensed) it, ...
... In most jugs the cartridge needs to be changed every few weeks. Even water that has been treated and passed through a filter jug is not pure. It will still contain many dissolved substances. But despite this it is safe to drink. We can get totally pure water by distilling(boiled then condensed) it, ...
GENERAL CHEMISTRY SECTION IV: THERMODYNAMICS
... But we are only concerned with the system (which, in chemistry, is the chemical reaction). And we like to isolate the chemical reaction/system by putting it in a closed environment; everything outside of that closed environment is the surroundings. ...
... But we are only concerned with the system (which, in chemistry, is the chemical reaction). And we like to isolate the chemical reaction/system by putting it in a closed environment; everything outside of that closed environment is the surroundings. ...
High School Chemistry Essential Questions
... High School Chemistry Essential Questions A. What is the kinetic-particle model of matter, what evidence do we have for the kinetic-particle model of matter, and how do we use the kinetic-particle model of matter to represent, analyze, and communicate structure and relationships in chemical systems ...
... High School Chemistry Essential Questions A. What is the kinetic-particle model of matter, what evidence do we have for the kinetic-particle model of matter, and how do we use the kinetic-particle model of matter to represent, analyze, and communicate structure and relationships in chemical systems ...
Chemical Reactions and Enzymes
... – process by which atoms or groups of atoms in substances are reorganized into different substances ...
... – process by which atoms or groups of atoms in substances are reorganized into different substances ...
Unit 10 – The Mole
... As you know, the mass of an element on the periodic table is a weighted average of all the naturallyoccurring isotopes of that element. Originally, we said that the unit for the mass of an element was ____________. From now on, we will be substituting ___________ as the unit for the mass of an eleme ...
... As you know, the mass of an element on the periodic table is a weighted average of all the naturallyoccurring isotopes of that element. Originally, we said that the unit for the mass of an element was ____________. From now on, we will be substituting ___________ as the unit for the mass of an eleme ...
Many thermal and chemical reactions occur during the roasting
... to the derivation of Nicotinic Acid remains linear. The control model of this reaction ratio is a time/temperature/energy relationship. The environment temperature (ET) establishes the pyrolysis region for the desired chemical reactions while the energy value (BTU) and system transfer efficiency (ST ...
... to the derivation of Nicotinic Acid remains linear. The control model of this reaction ratio is a time/temperature/energy relationship. The environment temperature (ET) establishes the pyrolysis region for the desired chemical reactions while the energy value (BTU) and system transfer efficiency (ST ...
Chemistry 12 – Unit 3 – Chapter 5 – Thermochemistry
... When energy changes are measured in a chemical reaction, the system is the reaction mixture being studied, and the surroundings are the flask, the room, and the rest of the universe. The energy change is the difference between final and initial states (E = Efinal - Einitial). Any energy that flows ...
... When energy changes are measured in a chemical reaction, the system is the reaction mixture being studied, and the surroundings are the flask, the room, and the rest of the universe. The energy change is the difference between final and initial states (E = Efinal - Einitial). Any energy that flows ...
9077590 Chem. Rege. Jan. 01
... completes the statement or answers the question. Record your answer on the separate answer sheet in accordance with the directions on the front page of this booklet. 1 The heat absorbed when ice melts can be measured in a unit called a (1) torr (3) mole (2) degree (4) calorie ...
... completes the statement or answers the question. Record your answer on the separate answer sheet in accordance with the directions on the front page of this booklet. 1 The heat absorbed when ice melts can be measured in a unit called a (1) torr (3) mole (2) degree (4) calorie ...
Stoichiometry PP
... 2C2H2 + 5 O2 4CO2 + 2 H2O If 3.84 moles of C2H2 are burned, how many moles of O2 are needed? (9.60 mol) How many moles of C2H2 are needed to produce 8.95 mole of H2O? (8.95 mol) If 2.47 moles of C2H2 are burned, how many moles of CO2 are formed? (4.94 mol) ...
... 2C2H2 + 5 O2 4CO2 + 2 H2O If 3.84 moles of C2H2 are burned, how many moles of O2 are needed? (9.60 mol) How many moles of C2H2 are needed to produce 8.95 mole of H2O? (8.95 mol) If 2.47 moles of C2H2 are burned, how many moles of CO2 are formed? (4.94 mol) ...
electrical energy and capacitance
... (5) EF = C2H5 = 29.07 g/mol (6) MF = 58.12 g/mol (7) MF = n(EF) (8) n = MF / EF (9) n = 58.12 / 29.07 (10) n = 2 (11) MF = (2)(C2H5) (12) MF = C4H10 MOLE TO MOLE CONVERSIONS Chemical equations are quantitative because they tell us how many reactants and products interact in a given reaction. In part ...
... (5) EF = C2H5 = 29.07 g/mol (6) MF = 58.12 g/mol (7) MF = n(EF) (8) n = MF / EF (9) n = 58.12 / 29.07 (10) n = 2 (11) MF = (2)(C2H5) (12) MF = C4H10 MOLE TO MOLE CONVERSIONS Chemical equations are quantitative because they tell us how many reactants and products interact in a given reaction. In part ...
3 - Study Hungary
... A: the atomic number decreases by 2 and the mass number by 4. B: the atomic number decreases by 4 and the mass number by 2. C: the atomic number increases by 1 and the mass number doesn’t change. D: the loss of a neutron decreases the mass number by 1 and the charge by 1. E: the loss of a proton dec ...
... A: the atomic number decreases by 2 and the mass number by 4. B: the atomic number decreases by 4 and the mass number by 2. C: the atomic number increases by 1 and the mass number doesn’t change. D: the loss of a neutron decreases the mass number by 1 and the charge by 1. E: the loss of a proton dec ...
AS specification - word format File
... f use chemical equations to calculate volumes of gases and vice versa using the concepts of amount of substance and molar volume of gases, eg calculation of the mass or volume of CO2 produced by combustion of a hydrocarbon (given a molar volume for the gas) g use chemical equations and experimental ...
... f use chemical equations to calculate volumes of gases and vice versa using the concepts of amount of substance and molar volume of gases, eg calculation of the mass or volume of CO2 produced by combustion of a hydrocarbon (given a molar volume for the gas) g use chemical equations and experimental ...
CHEM%1212K% Final%Exam% Summer%2011% K
... 7.%%At%425oC,%K%=%4.18%x%10J9%for%the%reaction%2HBr(g)% %H2(g)%+%Br2(g).%%If%0.20%bar%of% HBr(g),%and%0.010%bar%of%both%H2(g)%and%Br2(g)%are%introduced%into%a%container,%then% which%expression%best%represents%the%equilibrium%pressure%of%HBr?% ...
... 7.%%At%425oC,%K%=%4.18%x%10J9%for%the%reaction%2HBr(g)% %H2(g)%+%Br2(g).%%If%0.20%bar%of% HBr(g),%and%0.010%bar%of%both%H2(g)%and%Br2(g)%are%introduced%into%a%container,%then% which%expression%best%represents%the%equilibrium%pressure%of%HBr?% ...
The Mole
... • Step 1: Assume that the total mass of the substance is 100g and express the percent of each element in grams. 40.5g S and 59.95g O • Step 2: Convert the mass of each element to moles. • Step 3: Convert the mole ratios to whole numbers by dividing by the smallest mole value. ...
... • Step 1: Assume that the total mass of the substance is 100g and express the percent of each element in grams. 40.5g S and 59.95g O • Step 2: Convert the mass of each element to moles. • Step 3: Convert the mole ratios to whole numbers by dividing by the smallest mole value. ...
mole ratio
... • On some occasions at the end of a limiting reagent problem, you’ll be asked how much of the excess reactant is leftover when the reaction completes. To do this: – Step 1: Use the moles of limiting reagent. – Step 2: Calculate how many moles of excess reagent are needed to react with the limiting r ...
... • On some occasions at the end of a limiting reagent problem, you’ll be asked how much of the excess reactant is leftover when the reaction completes. To do this: – Step 1: Use the moles of limiting reagent. – Step 2: Calculate how many moles of excess reagent are needed to react with the limiting r ...
1442 Final Review
... 35. What is the best definition of a Brønsted-Lowry base? a) electron-pair acceptor b) electron-pair donor *c) proton acceptor d) proton donor e) produces hydroxide ions in aqueous solutions 36. If the concentration of hydroxide ion in a certain solution is 5.8 x 10-3 M, what is the pH of the soluti ...
... 35. What is the best definition of a Brønsted-Lowry base? a) electron-pair acceptor b) electron-pair donor *c) proton acceptor d) proton donor e) produces hydroxide ions in aqueous solutions 36. If the concentration of hydroxide ion in a certain solution is 5.8 x 10-3 M, what is the pH of the soluti ...
Section 1B
... After finding the masses of each element, these masses can be converted into moles. The ratio of these mole values gives the empirical formula. Example 1: To find ...
... After finding the masses of each element, these masses can be converted into moles. The ratio of these mole values gives the empirical formula. Example 1: To find ...
5. Formulae, equations and amounts of substance
... Using a gas syringe Gas syringes can be used for a variety of experiments where the volume of a gas is measured, possibly to work out moles of gas or to follow reaction rates. The volume of a gas depends on pressure and temperature so when recording volume it is important to note down the temperatur ...
... Using a gas syringe Gas syringes can be used for a variety of experiments where the volume of a gas is measured, possibly to work out moles of gas or to follow reaction rates. The volume of a gas depends on pressure and temperature so when recording volume it is important to note down the temperatur ...
Solute
... in fixed positions. Liquid – definite volume but indefinite shape; particles close together but not in fixed positions Gas – neither definite volume nor definite shape; particles are at great distances from one another Plasma – high temperature, ionized phase of matter as found on the sun. ...
... in fixed positions. Liquid – definite volume but indefinite shape; particles close together but not in fixed positions Gas – neither definite volume nor definite shape; particles are at great distances from one another Plasma – high temperature, ionized phase of matter as found on the sun. ...
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.