Search found 77 matches
- Mon Mar 16, 2020 1:04 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Catalyst
- Replies: 9
- Views: 626
Catalyst
How can we tell which compound is the catalyst based on the elementary reactions? How would we determine the reaction mechanism when we are not told which reaction is slow and which is fast?
- Mon Mar 16, 2020 1:03 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Initial vs Unique Rates
- Replies: 3
- Views: 293
Initial vs Unique Rates
What is the difference between an initial rate for a reactant, and its unique rate? Does this tie into the inverse of the stoichiometric coefficient?
- Mon Mar 16, 2020 1:00 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Activation Energy
- Replies: 3
- Views: 377
Activation Energy
How does an increase in temperature lower the activation energy? If we were given two reactions, 1 endothermic and the other exothermic, how would an increase in temperature affect the rate constant?
- Fri Mar 13, 2020 5:29 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Irreversible System
- Replies: 2
- Views: 294
Irreversible System
How would we find the change in entropy for an irreversible system? Why would the entropy of the surroundings equal 0?
- Fri Mar 13, 2020 5:25 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: factors of Gibbs free energy
- Replies: 2
- Views: 276
Re: factors of Gibbs free energy
The equilibrium constant, K, shows where the system reaches equilibrium, so that no work is being done by the system (Gibbs=0). Different value of Q will show how much work a system can do, and the spontaneity of the system. Because the Gibbs free energy shows the maximum available work a system can...
- Fri Mar 13, 2020 5:21 pm
- Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
- Topic: 3rd law
- Replies: 3
- Views: 374
Re: 3rd law
As temperature reaches zero, the entropy of the system reaches a constant value that reflects the degeneracy of the ground state.
- Fri Mar 13, 2020 5:20 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Enthalpies
- Replies: 1
- Views: 236
Enthalpies
If an ice cube is dropped into a hot coffee cup at 300K, how would we be able to determine how much ice would be needed to drop the temperature to 250K?
- Fri Mar 13, 2020 5:18 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Reduction Potential
- Replies: 4
- Views: 333
Reduction Potential
If the reduction potentials are both negative, do we take the largest value as the cathode, and the smallest as the anode?
- Fri Mar 13, 2020 5:17 pm
- Forum: Second Order Reactions
- Topic: Second Order Rxn
- Replies: 2
- Views: 226
Second Order Rxn
How would the graph of a second order reaction look like? What can you find with the second order equation ?
- Wed Mar 04, 2020 9:13 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: platinum
- Replies: 2
- Views: 246
Re: platinum
If the compounds in the redox reaction are in aqueous or gaseous form, they need a conductor to help with the movement of electrons from one cell to the other. Platinum Pt(s) is a common conductor that can be used.
- Wed Mar 04, 2020 9:12 pm
- Forum: General Rate Laws
- Topic: First vs Second Order Rate Laws
- Replies: 3
- Views: 327
First vs Second Order Rate Laws
What is the difference between a first and second order reaction? Does increasing the concentration of a reactant increase the rate of the reaction?
- Wed Mar 04, 2020 9:09 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Changes in Q
- Replies: 3
- Views: 327
Changes in Q
If we decreased the concentration of a reactant, what would happen to the cell potential of the cell? If we decreased the mass of a reactant, what would happen to the cell potential?
- Wed Mar 04, 2020 9:07 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Standard Cell Potentials
- Replies: 1
- Views: 180
Standard Cell Potentials
What does it mean if the standard cell potential is negative? Will it be an oxidation reaction?
- Wed Mar 04, 2020 9:05 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Change in Internal Energy
- Replies: 3
- Views: 387
Change in Internal Energy
When would we use the change in U = q +w, and when would we use the change in U= H-PVdv? Does it matter which equation you use when calculating the change in internal energy?
- Thu Feb 27, 2020 7:25 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagrams
- Replies: 2
- Views: 250
Cell Diagrams
Do electrolytes flow to the anode or cathode end? What is the purpose of the electrolytes in the redox reaction?
- Thu Feb 27, 2020 7:23 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagrams
- Replies: 3
- Views: 255
Cell Diagrams
When drawing the cell diagrams, do we include water or represent it as H+ ions?
- Thu Feb 27, 2020 7:23 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Gibbs Free Energy
- Replies: 2
- Views: 208
Gibbs Free Energy
Conceptually, why does a negative cell potential produce a positive (non-spontaneous) Gibbs free energy?
- Thu Feb 27, 2020 7:21 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Non-Standard Potential
- Replies: 3
- Views: 287
Non-Standard Potential
How can we determine if the equilibrium constant of a reaction is greater than or less than 1 based on the Nernst equation?
- Thu Feb 27, 2020 7:20 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Concentration Cells
- Replies: 6
- Views: 536
Concentration Cells
Whats the difference between a concentration cell and a galvanic cell? Does one of them do more work than the other cell?
- Wed Feb 19, 2020 4:23 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs free energy
- Replies: 4
- Views: 358
Gibbs free energy
What does it tell us if the Gibbs free energy of the products is greater than the Gibbs free energy of the reactants?
- Wed Feb 19, 2020 4:21 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs Free Energy
- Replies: 2
- Views: 254
Gibbs Free Energy
If the Gibbs free energy value is positive, does it also imply that the reaction is endothermic? Or could the reaction also be exothermic?
- Wed Feb 19, 2020 4:19 pm
- Forum: Balancing Redox Reactions
- Topic: Redox reactions
- Replies: 2
- Views: 196
Redox reactions
Why do we have to include the OH- or H+ if a reaction is placed in an acidic or basic solution when balancing a redox reaction?
- Wed Feb 19, 2020 4:17 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Potentials
- Replies: 2
- Views: 191
Cell Potentials
How does the standard electrode potential differ from the electrode potential?
- Wed Feb 19, 2020 4:16 pm
- Forum: Balancing Redox Reactions
- Topic: Balancing Redox
- Replies: 5
- Views: 393
Balancing Redox
How do you know what charge a compound has? Is it usually given or do you simply have to memorize the charges of molecules?
- Tue Feb 11, 2020 10:42 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Decreasing pressure
- Replies: 7
- Views: 616
Decreasing pressure
Why does decreasing pressure cause the reaction to shift toward the side that has more moles?
- Tue Feb 11, 2020 10:40 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Solids and Equilibrium Constant
- Replies: 2
- Views: 118
Solids and Equilibrium Constant
Why does adding more solid to a reaction not cause the equilibrium to shift? If I added more of a reactant, shouldn't the products increase as well regardless if it is solid?
- Tue Feb 11, 2020 10:39 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Entropy
- Replies: 4
- Views: 329
Entropy
Why does increasing the temperature cause an increase in the entropy of the system?
- Tue Feb 11, 2020 10:37 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Spontaneous
- Replies: 23
- Views: 1279
Spontaneous
How do we determine if a reaction is spontaneous? What does having a Gibbs free energy of 0 mean relative to the energy of the reaction?
- Tue Feb 11, 2020 10:35 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: State Function
- Replies: 3
- Views: 171
State Function
What is the difference between a state function and a path function? Are entropy, enthalpy and Gibbs free energy all examples of state functions?
- Fri Feb 07, 2020 3:03 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: HW 4.15
- Replies: 2
- Views: 135
HW 4.15
How would you solve this problem? Hydrochloric acid oxidizes zinc metal in a reaction that produces hydrogen gas and chloride ions. A piece of zinc metal of mass 8.5 g is dropped into an apparatus containing 800.0 mL of 0.500 m HCl(aq). If the initial temperature of the hydrochloric acid solution is...
- Fri Feb 07, 2020 2:28 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Entropy
- Replies: 2
- Views: 144
Entropy
Why is the entropy of the universe always positive? And why does a larger temperature mean it has a smaller change in entropy?
- Fri Feb 07, 2020 2:27 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Change in internal energy
- Replies: 3
- Views: 181
Change in internal energy
When is the change in internal energy equal to 0? When is it equal to q? And what does it mean when the system is isothermal and irreversible?
- Fri Feb 07, 2020 2:25 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Entropy
- Replies: 2
- Views: 140
Entropy
What exactly is residual entropy and how would we calculate it if we were given a 50 molecules of NH3?
- Tue Feb 04, 2020 11:05 am
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: negative entropy
- Replies: 4
- Views: 189
Re: negative entropy
Negative entropy means there is a decrease in the disorder of the system or increase in the order of the system.
- Tue Feb 04, 2020 11:02 am
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: isothermal reversible expansion
- Replies: 2
- Views: 120
Re: isothermal reversible expansion
Yes, when the reaction is isothermal and reversible, you use that equation to calculate the change in entropy of the system.
- Tue Feb 04, 2020 11:00 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: 4D.7
- Replies: 1
- Views: 108
4D.7
What would be the net moles of the reaction if the reaction is OF2 + H20--> O2 + 2HF. How would I solve the problem given that I have 1 mole of OF2 and the change in enthalpy is equal to -318kJ?
- Tue Feb 04, 2020 10:47 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: reversible v irreversible work
- Replies: 3
- Views: 227
Re: reversible v irreversible work
For reversible work, the pressure gradually decreases as the volume of the system expands. At the start, the pressure outside the system matches the pressure inside of the system, so through infinitesimal changes in pressure, the volume of the gas will expand, and keep an equilibrium state with its ...
- Tue Feb 04, 2020 10:39 am
- Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
- Topic: Microstate
- Replies: 1
- Views: 89
Microstate
What exactly are microstates and how do they help determine the disorderness(entropy) of a system?
- Sat Feb 01, 2020 1:42 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Enthalpy of Rxn
- Replies: 9
- Views: 442
Enthalpy of Rxn
If the enthalpy of a reaction is 300kJ/mol, and we have 0.05mol of th substance, do we multiply or divide by the moles of the substance to find the enthalpy of the reaction?
- Thu Jan 30, 2020 9:09 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Heat Capacity
- Replies: 2
- Views: 130
Heat Capacity
If we are given grams of a substance, is it better to convert it to moles and use the molar heat capacity, or should I keep it in grams?
- Thu Jan 30, 2020 9:08 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Heat Capacity
- Replies: 2
- Views: 157
Heat Capacity
How can we use the standard enthalpy of formation to calculate the enthalpy of a reaction given a certain amount of moles. For instance, if we find the enthalpy of the reaction, how do you find the enthalpy at a specific mole value (i.e. 0.4 mol of a reactant)?
- Thu Jan 30, 2020 9:05 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Calorimeter
- Replies: 4
- Views: 253
Calorimeter
If we are given the heat capacity of the calorimeter, do we use that heat capacity to calculate the heat released by a chemical reaction? Or do we use the heat capacity of the molecules in the calorimeter?
- Thu Jan 30, 2020 9:03 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Enthalpy at Constant Pressure
- Replies: 2
- Views: 144
Enthalpy at Constant Pressure
Is enthalpy at constant pressure mean that the system has to be at 1.0atm and 25 degrees celsius? Or is it simply that it should be at 25 degrees celsius?
- Thu Jan 30, 2020 8:31 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Homework question 4B.13
- Replies: 5
- Views: 291
Re: Homework question 4B.13
Make sure you use the correct gas constant. You probably used the 0.82 atm.L/mol.K, which got you the value that you have. Use 8.3145 J/mol.K and you should get the answer from the manual.
- Thu Jan 23, 2020 5:41 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Temperature
- Replies: 6
- Views: 230
Temperature
Why does temperature affect the K? Does increasing heat for an exothermic reaction shift it to the reactants or products?
- Thu Jan 23, 2020 5:39 pm
- Forum: Ideal Gases
- Topic: Pressure
- Replies: 2
- Views: 160
Pressure
Why doesn't adding an inert gas to a reaction increase the pressure and thus move the direction of the reaction a certain way?
- Thu Jan 23, 2020 5:30 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Hw problem 5.35 help
- Replies: 3
- Views: 168
Re: Hw problem 5.35 help
To calculate the equilibrium constant, you use the ratio of the equilibrium concentrations of the products over the reactants. At equilibrium, the concentrations of A,B, and C should not change. We see that at the end of the graph. A was the reactant, while B and C were the products. The equilibrium...
- Thu Jan 23, 2020 5:25 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Buffers
- Replies: 2
- Views: 94
Buffers
How do buffers differ from the usual way that we calculate the concentrations using the ICE table?
- Thu Jan 23, 2020 5:23 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: pKa/Pkb vs pH/pOH
- Replies: 3
- Views: 171
Re: pKa/Pkb vs pH/pOH
The pKa and pKb tells us how well a compound dissociates in a solution(how fully it releases hydrogen or hydroxide ions) and tells us the strength of the acid or base. The pH tells us the concentration of H30+ ions that a compound gives off when placed in a solution, while the pOH tells us the conce...
- Tue Dec 03, 2019 10:11 pm
- Forum: Bronsted Acids & Bases
- Topic: Acids and Bases
- Replies: 2
- Views: 154
Acids and Bases
Which is a stronger acid, CH3CH2OH or CH3COOH, and why? Is it due to the extra electronegative atom(the oxygen) or because of its resonance?
- Sun Nov 17, 2019 4:56 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 2E.19 b
- Replies: 2
- Views: 157
Re: 2E.19 b
By drawing VSEPR structure, it takes the shape of a tetrahedral for both of the carbons. It would look like two tetrahedral bonded together by the carbon. So H3C-CH2BeH. The H3C would be a tetrahedral and so would the CH2BeH.
- Sun Nov 17, 2019 12:47 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Determining Polarity
- Replies: 3
- Views: 254
Re: Determining Polarity
You would draw out the lewis structure and then compare the electronegativity of each of the atoms attached to the central atom. If there is an uneven distribution of charge throughout the molecule, then you would call the molecule polar.
- Sun Nov 17, 2019 12:44 pm
- Forum: Dipole Moments
- Topic: ion-dipole moments
- Replies: 3
- Views: 167
Re: ion-dipole moments
An ion-dipole interaction is stronger than a dipole-dipole interaction because an ion has a stronger charge than a polar molecule.
- Sun Nov 17, 2019 12:37 pm
- Forum: Dipole Moments
- Topic: Dipole moments in trigonal bipyramidal shaped molecules
- Replies: 4
- Views: 586
Re: Dipole moments in trigonal bipyramidal shaped molecules
For molecules that are highly symmetrical, like the trigonal bipyramidal, octahedral, and tetrahedral, the individual dipoles will usually cancel out, as they are typically non-polar molecular structures. However, if some of the atoms attached to a trigonal bipyramidal molecule, for example, are not...
- Sun Nov 17, 2019 12:25 pm
- Forum: Dipole Moments
- Topic: Polar vs. Non-polar bonds
- Replies: 2
- Views: 196
Re: Polar vs. Non-polar bonds
You could compare the sizes of the two atoms and the number of protons that each atom has. Larger atoms have more orbitals and thus a greater amount of shielding electrons. The effective nuclear charge would not be as great as it would be for smaller atoms, and will be less able to pull electrons to...
- Sat Nov 16, 2019 6:49 pm
- Forum: Electronegativity
- Topic: Electronegativity
- Replies: 10
- Views: 679
Electronegativity
What exactly causes an atom to have more electronegativity than other atoms?
- Sat Nov 16, 2019 6:48 pm
- Forum: Dipole Moments
- Topic: Dipole Moment
- Replies: 3
- Views: 131
Dipole Moment
Does electronegativity have to do with a dipole moment? Are we supposed to know how to calculate a dipole moment on a test?
- Sat Oct 26, 2019 7:54 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configuration
- Replies: 3
- Views: 253
Electron Configuration
So how does Lavelle want us to write the electron configuration of transition metals? Like for instance Vanadium, does he want us to write it like [Ar]4s2 3d3 or [Ar]4s1 3d4?
- Fri Oct 25, 2019 7:09 pm
- Forum: Trends in The Periodic Table
- Topic: Effective Nuclear Charge
- Replies: 2
- Views: 114
Re: Effective Nuclear Charge
The equation is Zeff= Z-S, where Z is the atomic number and S is the number of shielding electrons(non-valence electrons).
- Fri Oct 25, 2019 7:01 pm
- Forum: DeBroglie Equation
- Topic: Post-assessment question 34
- Replies: 2
- Views: 152
Re: Post-assessment question 34
I believe the answer was 1.00 x 10^5m/s, not the answer you gave. The rest of you answer is correct, in that it is reasonable because the electron is moving slower than the speed of light.
- Fri Oct 25, 2019 6:49 pm
- Forum: Trends in The Periodic Table
- Topic: First vs. Second Ionization Energies
- Replies: 2
- Views: 137
Re: First vs. Second Ionization Energies
Ionization energy is the energy required to remove an electron from the valence shell. By removing one electron, there are more protons than electrons now, and thus the electrons are more tightly bound to the nucleus. Thus, the second ionization energy will be higher than the first now that it has t...
- Thu Oct 24, 2019 3:57 pm
- Forum: Ionic & Covalent Bonds
- Topic: HW 2.A.1 (c) - valence electrons for elements in d block
- Replies: 1
- Views: 219
Re: HW 2.A.1 (c) - valence electrons for elements in d block
An element is most stable when its orbitals are full or half-full. In the case of Manganese, it has 7 valence electrons as you can see from its electron configuration [Ar]4s2 3d5, by counting the 2 electrons from the s-orbital and the 5 from the d-orbital. Because it is at a half filled d-orbital, i...
- Thu Oct 24, 2019 3:48 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 2A.5: What happens with s and d orbitals?
- Replies: 2
- Views: 143
Re: 2A.5: What happens with s and d orbitals?
The electron configurations of Thallium is [Xe]4f14 5d10 6s2 6p1. Because it is Tl^+3, Thallium has lost 3 electrons. You remove the electrons in the order of the highest energy level, which in this case, is n=6. When you take the 3 away, you are left with [Xe]4f14 5d10.
- Sun Oct 20, 2019 4:06 pm
- Forum: Properties of Electrons
- Topic: Shared Electrons
- Replies: 4
- Views: 274
Re: Shared Electrons
Hund's Rule tells us that because of the repulsion of electrons, they will first try to occupy different orbitals while having parallel spin, which has less energy than opposite spin electrons. Because there are 3 p orbitals, they will try to fill up each orbital first until they other electrons beg...
- Sun Oct 20, 2019 3:50 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: h bar formula [ENDORSED]
- Replies: 4
- Views: 419
Re: h bar formula [ENDORSED]
The more correct one to use is the h/4pi.
- Sun Oct 20, 2019 3:47 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configuration
- Replies: 5
- Views: 240
Electron Configuration
What exactly is the order that electrons fill up orbitals? With what atoms do we start using the d-orbital?
- Sun Oct 20, 2019 3:44 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Quantum Numbers
- Replies: 7
- Views: 275
Quantum Numbers
How do we know when to put the spin number? How does an electron's spin affect its behavior?
- Sat Oct 12, 2019 7:43 pm
- Forum: Properties of Electrons
- Topic: Wavelength and Electrons
- Replies: 4
- Views: 269
Re: Wavelength and Electrons
The wavelength of an electron is Wavelength=10^-12m
- Sat Oct 12, 2019 7:40 pm
- Forum: Properties of Electrons
- Topic: History of the QM Equations
- Replies: 2
- Views: 129
Re: History of the QM Equations
The three fundamental equations were developed in the 1920s.
- Sat Oct 12, 2019 7:39 pm
- Forum: Properties of Electrons
- Topic: Diffraction
- Replies: 2
- Views: 117
Re: Diffraction
Constructive interference is when the peaks and troughs of two waves match and thus increase the amplitude of the wave.
- Sat Oct 12, 2019 7:34 pm
- Forum: Properties of Electrons
- Topic: Planck's constant
- Replies: 2
- Views: 181
Re: Planck's constant
Yes Lavelle explained it within his video modules.
- Sat Oct 12, 2019 7:33 pm
- Forum: Properties of Electrons
- Topic: Weight of Particles
- Replies: 4
- Views: 245
Re: Weight of Particles
The mass of an electron is 9.109x10^-31. The mass of a proton and neutron is 1.67x10^-27.
- Fri Oct 04, 2019 8:45 am
- Forum: SI Units, Unit Conversions
- Topic: Bond Length
- Replies: 5
- Views: 374
Re: Bond Length
Bond length is the distance between the nuclei of two bonded atoms.
- Fri Oct 04, 2019 8:43 am
- Forum: Student Social/Study Group
- Topic: Final Jitters
- Replies: 457
- Views: 429454
Re: Final Jitters
Make sure you study repeatedly over a long period of time. Don't cram the night before or that will contribute to your anxieties. Sleep and eat well, and take deep breathes to calm yourself down. Before the test, it is best not to think about it at all to avoid starting up any unnecessary anxiety. W...
- Fri Oct 04, 2019 8:36 am
- Forum: Empirical & Molecular Formulas
- Topic: When should one start rounding in a problem?
- Replies: 11
- Views: 608
Re: When should one start rounding in a problem?
It is best to round by the end of the problem and keep the precision of numbers during the problem to reach a more accurate answer. If you round too early, you might get a slightly lower or higher answer than what is correct. I would keep it at 1.007 for the sake of accuracy.
- Fri Oct 04, 2019 8:35 am
- Forum: SI Units, Unit Conversions
- Topic: Why do we always need grams when solving a problem?
- Replies: 6
- Views: 615
Re: Why do we always need grams when solving a problem?
It is the accepted base SI unit that helps to standardize measurements so that scientists can more easily compare their findings using the same unit measurement.
- Fri Oct 04, 2019 8:30 am
- Forum: Significant Figures
- Topic: How does one read sig figs?
- Replies: 3
- Views: 185
Re: How does one read sig figs?
Any non-zero number is significant. A zero is significant if it precedes the decimal point (e.g. 0.2) or if after the decimal point, precedes a non-zero(e.g. 0.004). So it given 500400, it would have 4 sig figs because the two zeroes in the middle precedes a non-zero, which in this case is 4. The ze...