Search found 32 matches

by Kriti Goyal 4K 19
Sun Mar 17, 2019 12:20 am
Forum: Ideal Gases
Topic: K and Q
Replies: 4
Views: 11

Re: K and Q

The concentration of solids and liquids are unchanged in a reaction. so only gasses are included.
by Kriti Goyal 4K 19
Sun Mar 17, 2019 12:18 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: pseudo rate law
Replies: 7
Views: 26

Re: pseudo rate law

Pseudo rate law is just a method used to simplify second order reactions that have more than one reactants. You basically take one reactant in a very high concentration, so the second reactant seems insignificant compared to it and doesnt have a big impact on the rate law of the equation. Therefore ...
by Kriti Goyal 4K 19
Thu Mar 14, 2019 10:19 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Adding an Inert Gas
Replies: 4
Views: 18

Re: Adding an Inert Gas

An inert gas does not react with any of the compounds in the reaction, however it does increase . the pressure of the overall system. Since the amount of reactants/products doesnt change, their partial pressures remain the same and so the rates the the forward and backward reaction dont change either.
by Kriti Goyal 4K 19
Thu Mar 14, 2019 10:17 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 785675

Re: Post All Chemistry Jokes Here

Old chemists never die, they just stop reacting.
by Kriti Goyal 4K 19
Thu Mar 14, 2019 10:16 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 785675

Re: Post All Chemistry Jokes Here

Q: What do you call a tooth in a glass of water?
A: One molar solution.
by Kriti Goyal 4K 19
Thu Mar 14, 2019 10:15 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 785675

Re: Post All Chemistry Jokes Here

Did you know that you can cool yourself to -273.15˚C and still be 0k?
by Kriti Goyal 4K 19
Thu Mar 14, 2019 10:14 pm
Forum: Zero Order Reactions
Topic: Order distinction
Replies: 9
Views: 44

Re: Order distinction

You take into account the rate law . equation. the sum of the exponents of the reactants gives you the order.
by Kriti Goyal 4K 19
Thu Mar 14, 2019 10:12 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: catalyst vs intermediate
Replies: 9
Views: 23

Re: catalyst vs intermediate

A catalyst is added to the reaction to make it faster, it is part of the reactants but then is regenerated. An intermediate is formed in the reaction and then used up, it does not need to be specifically added.
by Kriti Goyal 4K 19
Sun Feb 24, 2019 5:28 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Predicting Standard Potential of Cells
Replies: 2
Views: 29

Re: Predicting Standard Potential of Cells

If the value for the reverse reaction is given, you can take the negative value, which would give you the oxidation potential for the reaction you need that you can plug in the other equation, Ecell= Ered + Eox
by Kriti Goyal 4K 19
Sun Feb 24, 2019 5:25 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Determining what is constant
Replies: 1
Views: 21

Re: Determining what is constant

Most of the time, it is stated if there is a change. Like if there isa change in volume or temperature, the question will state that it went from this value to this value. But if its just a single value given, it is assumed its constant because there is no change indicated, unless ofcourse we need t...
by Kriti Goyal 4K 19
Sun Feb 24, 2019 5:21 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Spontaneous?
Replies: 6
Views: 36

Re: Spontaneous?

you look at the change in Gibbs Free Energy (Delta G). if the value is negative, it is a spontaneous reaction, also called exergonic. if it has a positive value it is not spontaneous, also called endergonic.
by Kriti Goyal 4K 19
Sun Feb 24, 2019 5:18 pm
Forum: Balancing Redox Reactions
Topic: Oxidation
Replies: 4
Views: 36

Re: Oxidation

Its kinda of a process that was evolved from a more basic concept (kind of like the definition of Lewis Acids and /bases, going from giving or receiving H+ or OH- to a more broad one.) Similarly, the definition of oxidation was originally the addition of oxygen to a compound or the removal of Hydrog...
by Kriti Goyal 4K 19
Sun Feb 24, 2019 5:12 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: n value
Replies: 11
Views: 61

Re: n value

n is the number of moles so it would either be given to us or we calculate it using molar mass or using the ideal gas law( in which case Pressure Volume and Temperature will be given.)
by Kriti Goyal 4K 19
Sun Feb 24, 2019 5:10 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: gibbs free energy
Replies: 5
Views: 38

Re: gibbs free energy

Most of the times, we use Gibbs Free Energy to tell us about the spontaneity of a reaction. It is . state function and gives us a relationship between Enthalpy and Entropy. we say a reaction is spontaneous if its change in G is negative.
by Kriti Goyal 4K 19
Sun Feb 10, 2019 2:34 pm
Forum: Calculating Work of Expansion
Topic: Using Derivative/Integral Equations
Replies: 5
Views: 31

Re: Using Derivative/Integral Equations

The integrals are only for derivations. We . wont be asked to derive the equations, only to use them in solving problems
by Kriti Goyal 4K 19
Sun Feb 10, 2019 2:32 pm
Forum: Calculating Work of Expansion
Topic: Integrals
Replies: 3
Views: 27

Re: Integrals

I dont think we need to learn the derivations, but it may be a good idea to see where the relations came from and what conditions they are valid in
by Kriti Goyal 4K 19
Sun Feb 10, 2019 2:30 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 785675

Re: Post All Chemistry Jokes Here

Q: What do you do with a sick chemist?
A: If you can't helium, and you can't curium, then you might as well barium.
by Kriti Goyal 4K 19
Sun Feb 10, 2019 2:30 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 785675

Re: Post All Chemistry Jokes Here

Q: What is the chemical formula for "coffee"?
A: CoFe2
by Kriti Goyal 4K 19
Sun Feb 10, 2019 2:29 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 785675

Re: Post All Chemistry Jokes Here

Have you heard the one about a chemist who was reading a book about helium?
He just couldn't put it down.
by Kriti Goyal 4K 19
Sun Feb 10, 2019 2:25 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Value of Variable Kb
Replies: 4
Views: 41

Re: Value of Variable Kb

Kb is a constant value, the boltzmann Constant. The value will always be given, we dont need to memorize it. but it helps determine the entropy of a system
by Kriti Goyal 4K 19
Sun Feb 10, 2019 2:24 pm
Forum: Calculating Work of Expansion
Topic: Degeneracy
Replies: 3
Views: 41

Re: Degeneracy

Degeneracy is the number of possible ways to attain a certain energy state, like the number os electron configurations that can require the same energy level. This can be used to then determine entropy and spontaneity of a reaction
by Kriti Goyal 4K 19
Sun Feb 10, 2019 2:20 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Delta H
Replies: 4
Views: 31

Re: Delta H

q and H are interchangeable terms. Heat is the same thing as Enthalpy. However q is equal to U only when no work is done.
by Kriti Goyal 4K 19
Sun Feb 10, 2019 2:17 pm
Forum: Phase Changes & Related Calculations
Topic: Phase Changes
Replies: 11
Views: 149

Re: Phase Changes

Yes it is very important to understand the phase changes as a lot of the times questions may ask the complete heat difference of a phase change and at the time you need to be conscious of the heat required for changing phase even though the temperature does not change.
by Kriti Goyal 4K 19
Sun Feb 10, 2019 2:14 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Decreasing volume and chemical equilibrium
Replies: 8
Views: 77

Re: Decreasing volume and chemical equilibrium

If you increase the volume, the reaction will most likely shift to the side with fewer moles
by Kriti Goyal 4K 19
Thu Jan 24, 2019 5:12 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7337
Views: 785675

Re: Post All Chemistry Jokes Here

Helium walks into a bar,
The bar tender says "We don't serve noble gasses in here."
Helium doesn't react.
by Kriti Goyal 4K 19
Thu Jan 24, 2019 5:10 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: using Ka and Kb to predict strengths of acids and bases
Replies: 3
Views: 32

Re: using Ka and Kb to predict strengths of acids and bases

yes, the same concept will apply to bases. If Kb<10^-3, the base would considered weak. Similarly, if Kb>10^-3, the base is considered strong
by Kriti Goyal 4K 19
Thu Jan 24, 2019 5:08 pm
Forum: Phase Changes & Related Calculations
Topic: Why steam causes severe burns
Replies: 9
Views: 77

Re: Why steam causes severe burns

Think of it this way, when hot water comes in contact with your skin, there will a kind of be a heat energy exchange between the two to bring them to the same temperature, or to equilibrium temperature. Thus the water will cool down and the temperature of skin will rise. Now, as he stated in the wat...
by Kriti Goyal 4K 19
Thu Jan 24, 2019 5:00 pm
Forum: Phase Changes & Related Calculations
Topic: Water heating curve
Replies: 7
Views: 71

Re: Water heating curve

during the change of state, there is an initial rise all of the energy supplied through heat is used in breaking bonds, thus there is none residual to increase the temperature. Once all the bonds are broken, then the energy supplied can be used to increase the temperature of the substance as the cha...
by Kriti Goyal 4K 19
Thu Jan 24, 2019 4:56 pm
Forum: Phase Changes & Related Calculations
Topic: Reversible and Irreversible Process
Replies: 3
Views: 28

Re: Reversible and Irreversible Process

Most of the time if its a chemical reaction, you can tell by the arrows, if it is an equilibrium arrow, its reversible and if it is a one sided arrow, it is irreversible. However when it comes to change of state and matter, processes like melting and freezing etc are usually reversible as they are t...
by Kriti Goyal 4K 19
Thu Jan 24, 2019 4:53 pm
Forum: Phase Changes & Related Calculations
Topic: Temperature vs. heat vs. energy
Replies: 4
Views: 43

Re: Temperature vs. heat vs. energy

Temperature is a measure of the average kinetic energy of a substance whereas heat being transferred.
by Kriti Goyal 4K 19
Sat Jan 19, 2019 5:29 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Weak Acid & Salt
Replies: 4
Views: 39

Re: Weak Acid & Salt

Because it is a salt, KNO2 will completely dissociate in a solution. Now when you write the reaction both K+ and NO2- show up both sides of the equation, NO2- on the product side does not have the same concentration as the NO2- on the reactant side as it adds up to the concentration of NO2- dissocia...
by Kriti Goyal 4K 19
Sat Jan 19, 2019 5:18 pm
Forum: Student Social/Study Group
Topic: ICE Table
Replies: 6
Views: 61

Re: ICE Table

ICE tables are usually used when you are given the initial concentration of a certain substance in the reaction and need to identify the concentration of another substance(usually hydronium or hydroxide ions you need to calculate pH or pOH).

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