Name: ______KEY__________________ Date: ______ CHM 130
... CHM 130, Exam 3: Chapters 9, 10, 11, and 13 (and some of 14) Show all work and clearly mark all answers for full credit. 16. (4 pts) “Joe” decides to throw 3.45 grams of solid sodium into a “friend’s” pool. How many moles of sodium is this? 3.45 g Na x (1 mol / 22.99 g) = 0.150 mol Na ...
... CHM 130, Exam 3: Chapters 9, 10, 11, and 13 (and some of 14) Show all work and clearly mark all answers for full credit. 16. (4 pts) “Joe” decides to throw 3.45 grams of solid sodium into a “friend’s” pool. How many moles of sodium is this? 3.45 g Na x (1 mol / 22.99 g) = 0.150 mol Na ...
Fall 2013 Final practice questions w/o solution
... A) B has electrons in p orbitals, so it is lower in energy. B) Li does not want to gain an electron because it already has a half-full s orbital. C) B is a smaller atom, so its valence electrons are more tightly held. D) B is farther to the right in the same row as Li. E) The gain of an electron fil ...
... A) B has electrons in p orbitals, so it is lower in energy. B) Li does not want to gain an electron because it already has a half-full s orbital. C) B is a smaller atom, so its valence electrons are more tightly held. D) B is farther to the right in the same row as Li. E) The gain of an electron fil ...
Answers to Selected Questions and Problems
... Anna and Bill would have observed kinetic energy from the movement of the welder and the motion of the sparks. The sparks would have glowed, indicating heat, light, and chemical energy. The molecules in image A have greater kinetic energy because they are moving faster. Any object that would move if ...
... Anna and Bill would have observed kinetic energy from the movement of the welder and the motion of the sparks. The sparks would have glowed, indicating heat, light, and chemical energy. The molecules in image A have greater kinetic energy because they are moving faster. Any object that would move if ...
Energy and Matter in Chemical Change Science 10
... flowing (dependent variable) changes in response--you observe that the water flow increases. The number of dependent variables in an experiment varies, but there is often more than one. ...
... flowing (dependent variable) changes in response--you observe that the water flow increases. The number of dependent variables in an experiment varies, but there is often more than one. ...
Molar Mass
... • Are written from molar mass • Relate grams and moles of an element or compound. Example: Write molar mass factors for methane CH4 used in gas cook tops and gas heaters. Molar mass: 1 mol CH4 = 16.04 g Conversion factors: 16.04 g CH4 1 mol CH4 ...
... • Are written from molar mass • Relate grams and moles of an element or compound. Example: Write molar mass factors for methane CH4 used in gas cook tops and gas heaters. Molar mass: 1 mol CH4 = 16.04 g Conversion factors: 16.04 g CH4 1 mol CH4 ...
Chp 5 Circle the correct answer Consider three 1
... 3.You have two samples of the same gas in the same size container, with the same pressure. The gas in the first container has a kelvin temperature four times that of the gas in the other container. The ratio of the number of moles of gas in the first container compared to that in the second is a) 1 ...
... 3.You have two samples of the same gas in the same size container, with the same pressure. The gas in the first container has a kelvin temperature four times that of the gas in the other container. The ratio of the number of moles of gas in the first container compared to that in the second is a) 1 ...
Key
... lowest → B < C = D < A ← highest There are 6 electrons, which fill orbitals B, C, and D. iii. What would you predict for N–O bond order, and how does this compare to the answer you get from Lewis electron structures? There is a σ bond between the N and each O, and one π bonding pair (in orbital A) d ...
... lowest → B < C = D < A ← highest There are 6 electrons, which fill orbitals B, C, and D. iii. What would you predict for N–O bond order, and how does this compare to the answer you get from Lewis electron structures? There is a σ bond between the N and each O, and one π bonding pair (in orbital A) d ...
Skill Sheet 19-B Chemical Formulas
... Have you ever heard of sodium nitrate? It’s a preservative used in foods like hot dogs. The chemical formula for sodium nitrate is NaNO3. How many types of atoms does this compound contain? You are right if you said three: sodium, nitrogen, and oxygen. The nitrogen and oxygen atoms have a shared-ele ...
... Have you ever heard of sodium nitrate? It’s a preservative used in foods like hot dogs. The chemical formula for sodium nitrate is NaNO3. How many types of atoms does this compound contain? You are right if you said three: sodium, nitrogen, and oxygen. The nitrogen and oxygen atoms have a shared-ele ...
5.2 Calculations of Enthalpy Changes (SL/HL)
... Energy is required to break bonds. Energy is released when bonds form. In an exothermic reaction, the amount of energy required to break the bonds of the reactants is less then the amount of energy released when the bonds form in the products. Enthalpy ...
... Energy is required to break bonds. Energy is released when bonds form. In an exothermic reaction, the amount of energy required to break the bonds of the reactants is less then the amount of energy released when the bonds form in the products. Enthalpy ...
K eq
... • Equilibrium can only be achieved by starting with reactants. No - Equilibrium can also be achieved when starting with all of the paper wads on the product side of the room. ...
... • Equilibrium can only be achieved by starting with reactants. No - Equilibrium can also be achieved when starting with all of the paper wads on the product side of the room. ...
Balancing Chemical Reactions
... known as the reactants and the resulting substances are known as the products. • According to the law of conservation of mass, the total mass of reactants must equal the total mass of products for any given chemical reaction. Chapter menu ...
... known as the reactants and the resulting substances are known as the products. • According to the law of conservation of mass, the total mass of reactants must equal the total mass of products for any given chemical reaction. Chapter menu ...
Role of Water as a Solvent
... hydroxide and potassium hydrogenphthalate (KHP) to standardize the base solution, by placing 50.00 mg of solid potassium hydrogenphthalate in a flask with a few drops of an indicator. A buret is filled with the base, and the initial buret reading is 0.55 ml; at the end of the titration the buret rea ...
... hydroxide and potassium hydrogenphthalate (KHP) to standardize the base solution, by placing 50.00 mg of solid potassium hydrogenphthalate in a flask with a few drops of an indicator. A buret is filled with the base, and the initial buret reading is 0.55 ml; at the end of the titration the buret rea ...
The Mole
... Relative molecular mass This is the relative mass of simple molecular substances, such as chlorine, Cl2, and water, H2O. The relative molecular mass, Mr, is the weighted mean mass of a molecule of a compound compared to one-twelfth of the mass of the carbon–12 isotope. The relative molecular mass ca ...
... Relative molecular mass This is the relative mass of simple molecular substances, such as chlorine, Cl2, and water, H2O. The relative molecular mass, Mr, is the weighted mean mass of a molecule of a compound compared to one-twelfth of the mass of the carbon–12 isotope. The relative molecular mass ca ...
Reaction Rates/Chemical Kinetics
... H2 by the variable x. The balanced chemical equation tells us the relationship between the changes in the concentrations of the three gases: Fourth, we use the initial concentrations and the changes in concentrations, as dictated by stoichiometry, to express the equilibrium concentrations. With all ...
... H2 by the variable x. The balanced chemical equation tells us the relationship between the changes in the concentrations of the three gases: Fourth, we use the initial concentrations and the changes in concentrations, as dictated by stoichiometry, to express the equilibrium concentrations. With all ...
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.