Chemistry final Q4
If a temperatur of 34.4g of ethanol increases from 25°C to 53.8°C, how much heat has ben absorbed by the ethanol? (specific heat of ethanol is 2.44 J/(g°C)
Δt= 78.8 - 25 = 53.8°C q=mcΔt q=(34.4)(2.44)(53.8) q= 4515.76J
The presure of a sample of helium in a 1.0L container is 0.988 atm. What is the new pressure if the sample is placed in a 2.0L container?
Boyle's Law P₁*V₁=P₂*V₂ (.988)(1.0)=P₂(2.0) .988= P₂(2.0) P₂=.494 atm
What is the relationship among Boyle's, Charles's and Gay-Lussac's law?
Boyle's Law → States that the volume of a fixed amount of has held at a constant temperature verses inversely with the pressure. Charles's Law → States that the volume of a given mass of gas is directly proportional to its kelvin temperature at constant pressure. Gay-Lussac's Law → States that the pressure of a fixed mass of gas varies directly with the kelvin temperature when the volume remains constant.
What is the kinetic-molecular theory?
Describes the behavior of gasses in terms of particles in motion; makes several assumptions about size, motion, and energy of gas particles.
STP
Standard Temperature and pressure 1 Mol=22.4L EX: Moles? If you have 2.5L STP Mollar mass = 2.5L * 1Mol /22.4 =.11 Moles
What is the difference between an acidic solution and a basic solution?
Acidic solution → contains more hydrogen ions than hydroxide ions Basic solution → Contains more hydroxide ions than hydrogen ions
What is the difference between Arrhenius model and Bronsted-Lowry model of acids and bases?
Arrhenius model → a model of acids and bases states that contains hydrogen and ionizes to produce hydrogen ions in a solution and a base is a substance that contains a hydroxide group and disaccociates to produce hyrodxide ion in a aquas solution Bronsted-Lowry model → A model of acids and bases in which an acid is a hydrogen ion donor an a base is a hydrogen acceptor.
What is the ideal gas law? What is the relationship among the variables in the ideal gas law?
Describes the behavior of an ideal gas in terms of pressure, volume, temperature, and number of mass of gas.
Calculate the pH and the pOH of aqueous with the following concentrations at 298K [OH⁻]=1.0*10⁻⁶M [H⁺] =1.0*10⁻⁹M
Calculate the pH and the pOH of aqueous with the following concentrations at 298K [OH⁻]=1.0*10⁻⁶M pOH=6;pH=14-6=8 [H⁺] =1.0*10⁻⁹M pH=9; pOH=14-9=5
Calculate the pH of solutions having the following ion concentrations at 298K A: [H⁺] = 1.0*10⁻¹³M B: [OH⁻] = 1.0*10⁻³M
Calculate the pH of solutions having the following ion concentrations at 298K A: [H⁺] = 1.0*10⁻¹³M PH=2 B: [OH⁻] = 1.0*10⁻³M POH=8; PH=14-8=6
The Celsius temperature of a 3.00L sample of gas is lowered from 80°C to 30°C. What will be the resulting volume of this gas?
Charles's Law → States that the volume of a given mass of gas is directly proportional to its kelvin temperature at constant pressure. V₁*T₂ = V₂*T₁ 3.00*353=V₂*303 1,059= V₂*303 /303 = /303 3.5L = V₂
What is chemical potential energy? What is specific heat?
Chemical Potential energy → The energy stored in a substance because of its composition; most is released or absorbed as heat during chemical reactions or processes. Specific heat → the amount of heat required to raise the temperature of one gram of a given substance by one degree Celsius
What is the diffrence between chemical reactions and nuclear reactions?
Chemical reactions→ the process by which the atoms of one or more substances are rearranged to form different substances, occurrence can be indicated by change in the temperature, color, odor, and physical state. Nuclear reaction → a reaction that involves a change in the nucleus of an atom
What is the difference between endothermic and exothermic For Graph reference L1.1
Endothermic → A chemical reaction or process in which a greater amount of energy is required to break the existing bonds in the reactants that is released when the new bands form in the product molecules. Exothermic → A chemical reaction or process in which more energy is released then is required to break the bonds of the initial reactants. For Graph reference L1.1
What is energy? What is the Law of Conservation of Energy?
Energy → the capasity to do work or produce heat; exists as potiental energy, which is stored in an object due to its composition or position, and kinetic energy which is the energy stored in motion. Law of conservation of Energy → States that in any chemical reaction or physical process, energy may change from one form to another, but it is neither created nor destroyed.
What are some characteristics of gases?
Gasses → A form of matter that flows, to conform to the shape of its container, fills the containers entire volume, and is easily compressed.
Identify the conjugate acid-base pairs in each reaction? A: NH₄⁺(aq) + OH⁻(aq) ⇌ NH₃(aq) + H₂O(L) B: HBr(aq)+ H₂O(L) ⇌ H₃O⁺(aq) + Br⁻(aq)
Identify the conjugate acid-base pairs in each reaction? A: NH₄⁺(aq) + OH⁻(aq) ⇌ NH₃(aq) + H₂O(L) ACID BASE ⇌ Conj.BASE Conj.ACID B: HBr(aq)+ H₂O(L) ⇌ H₃O⁺(aq) + Br⁻(aq) ACID BASE ⇌ Conj.ACID Conj.BASE
What are some characteristics of liquids and solids?
Liquids → a form of matter that flows, has constant volume, and takes te shape of its container. Solids → a form of matter that has its own definite shape and volume, is in compressible, and expands only slightly when heated.
What are some of the phase changes and provide a brief description of each?
Solid to gas → Sublimination Gas to Solid → Desposition Solid to liquid → Melting Liquid to solid → Freezing Gas to liquid →Condensation Liquid to gas → Vaporization
What is the pressure, in atmospheres, of a .108mol sample of helium gas at a temperature of 20.0°C or 293°
T= 20°C + 273= 293°K PV=nRT P(.505)=(0.108)(0.0821)(293°K) .505 .505 P=5.4 atm
The concentration of either the H⁺ ion or the OH⁻ ion is given for four aqueius solutions at 298K. For each solution, calculate [H⁺] or [OH⁻]. State wether the solution is acidic , basic, or neutral? A: [H⁺]=1.0 * 10⁻¹³ M B: [OH⁻] = 1.0 * 10⁻³ M
The concentration of either the H⁺ ion or the OH⁻ ion is given for four aqueius solutions at 298K. For each solution, calculate [H⁺] or [OH⁻]. State wether the solution is acidic , basic, or neutral? A: [H⁺]=1.0 * 10⁻¹³ M [OH⁻][H⁺]=1.0*10⁻¹⁴ [OH⁻]=10⁻¹⁴ /10⁻¹³ =1.0*10⁻¹M B: [OH⁻] = 1.0 * 10⁻³ M [H⁺]=10⁻¹⁴ /10⁻¹³ =1.0*10⁻¹¹M
Write the ionization equaions and acid ionization constant expressions for each acid. HCIO₂ H₂SO₄
Write the ionization equaions and acid ionization constant expressions for each acid. HCIO₂ HCIO₂(aq) + H₂O(L) ⇌ H₃O⁺(aq) + CIO₂(aq) K= [H₃O⁺][CIO₂⁻] /HCIO₂ H₂SO₄ H₂SO₄ (aq)+H₂O(L) ⇌ H₃O⁺(aq)+HSO₄ (aq) Ka=[HSO⁴⁻][H₃O⁺] /H₂SO₄
Write the ionization equation and base ionization constant expression for the following bases? A: carbonate ion (CO₃²⁻) B: Hydrogen Sulfite ion (HSO₃⁻)
Write the ionization equation and base ionization constant expression for the following bases? A: carbonate ion (CO₃²⁻) CO₃²⁻(aq) + H₂O(L) ⇌ HCO₃¹⁻(aq) + OH¹⁻ (aq) Kb=[HCO₃⁻][OH⁻] /[co₃²⁻] B: Hydrogen Sulfite ion (HSO₃⁻) HSO₃⁻(aq) + H₂O(L) ⇌ HSO₃(aq) + OH⁻(aq) Kb=[H₂SO₄][OH⁻] /[HSO₃]
