CHEMISTRY COMMUNITY

Frankie Xu 2H

The rate at which a chemical reaction is taking place at a specific time is referred to as its instantaneous rate. On the other hand, the minimal amount of energy necessary for a reaction to take place is known as the activation energy of a chemical reaction.The instantaneous rate and activation ene...

Frankie Xu 2H

A substance's half-life can be impacted by external environmental factors like temperature and pressure by changing its chemical and physical properties. For instance, some substances may deteriorate more quickly at higher temperatures than others. The half-life of a substance can also be impacted b...

Frankie Xu 2H

It is all based on preference so both ways are correct! It is just easier to see the fraction version as it is easy to add 1 mol.

Frankie Xu 2H

I was also confused about this but from my general understanding, the reaction is moving forward, consuming reactants, and producing products. Hence, the instantaneous rate measures the speed at which the reaction is taking place.

Frankie Xu 2H

Measuring the reactant concentration over time and graphing the data on a graph with the reactant concentration on the y-axis and time on the x-axis is one common strategy. The reaction is likely first order if the resulting curve is linear and has a negative slope.

Frankie Xu 2H

If the rate of the reaction is unaffected by the concentration of one or more of the reactants, the reaction can be zero-order. In a zero-order reaction, the rate of the reaction does not change over time even though the reactant concentration does. For instance, the reaction might involve an excess...

Frankie Xu 2H

The anode, in an electrochemical cell, is the electrode where oxidation (the loss of electrons) takes place, and the cathode, is where reduction (the gain of electrons), takes place. The cathode's positive sign denotes the flow of electrons toward it, while the anode's negative sign denotes the flow...

Frankie Xu 2H

When balancing reactions, is there an easier way to know which side has OH- and H2O? As for now, I have been just using trial and error but please let me know if there is an easier method to do this

Frankie Xu 2H

n in the Nernst equation represents the charge of the ion being considered and it is essentially the moles of electrons in the reaction of the equation. For instance, if there were 2 electrons being transferred in the redox reaction, n would equal 2.

Frankie Xu 2H

The Van't Hoff equation's purpose is for calculating how a reaction's equilibrium constant will change as its temperature changes. A reaction's standard enthalpy change (H°) can also be calculated by measuring the equilibrium constant at various temperatures.

Frankie Xu 2H

When delta G is at equilibrium, the reactants and products are not favored and there is no net change so there is ultimately no energy for work.

Frankie Xu 2H

Whenever you see a ° sign, this would mean that it is in standard conditions; therefore, it is 273 K (0 degrees Celsius) and 1 atm pressure (or 105 Pa).

Frankie Xu 2H

As you stated, the gas constant is in Kelvin and so the temperature would also have to be in Kelvin to cancel out.

Frankie Xu 2H

Thank you for the advice! I have been feeling very lazy when making notes so this will definitely motivate me to make them better to help me in the future.

Frankie Xu 2H

Residual entropy is the entropy of a compound when at no energy that comes from positional disorder.

Frankie Xu 2H

As someone who did not do AP Chem or IB Chem, learning everything for scratch was very hard for me but I found it very helpful to attend the UA sessions and workshops as I had more practice with applying the concepts.

Frankie Xu 2H

Why are q and delta U the same value during constant volume?

Frankie Xu 2H

Why do solids not apply when the system does work on surroundings? Is it only gas?

Frankie Xu 2H

Why do solids not apply when the system does work on surroundings? Is it only gas?

Frankie Xu 2H

In an isolated system, energy and matter can not pass through, whereas, in an open system it is the opposite where energy and matter can pass through. A closed system can only exchange energy within its surroundings but not matter. I did not quite understand the systems at first but I am a visual le...

Frankie Xu 2H

Hi! I was wondering that as well. How useful are the step up sessions @anyone who went? Step-ups are very helpful for me especially with this upcoming midterm as they make worksheets and go over the steps on how to do it after. I would say if you were stuck with the textbook problems I would highly...

Frankie Xu 2H

All the step-ups are very useful as they work through the questions with you but I recommend attempting the worksheet beforehand.

Frankie Xu 2H

Endothermic: dissolving salt in water
Exothermic: freezing water into ice

Frankie Xu 2H

Melting is an endothermic process as it requires energy to break bonds and the phase change is from a solid to a liquid.

Frankie Xu 2H

Exothermic reactions are when heat is released so the surroundings get hotter so a phase change would be in condensation when it goes from vapor to liquid and freezing from a liquid to a solid.

Frankie Xu 2H

We are allowed to use scientific calculators on exams as Dr. Lavelle stated on his website, "All students need a simple scientific calculator (no graphing, no WiFi, etc.) and a laptop as all exams". I assume Dr. Lavelle didn't use calculators in class to save time.

Frankie Xu 2H

Yes! This was taken directly from Dr. Lavelle's Website which states, "All students need a simple scientific calculator (no graphing, no WiFi, etc.) and a laptop as all
exams".

Frankie Xu 2H

I think that we would still have lectures on these days, however, I believe you should ask the professor or TA directly. They might let us know closer to the midterm as well.

Frankie Xu 2H

Aliya Roserie 3I wrote:I also wanted to know.. How do we check to ensure we have posted 5 times each week?

The number of posts is shown near your name and you only need to post 3 times a week!

Frankie Xu 2H

The ICE table has positive or negative values based on the reactant or product as the reactants would be negative whereas the products would be positive.

Frankie Xu 2H

Q is called the reaction quotient in the current state whereas the K value is called the equilibrium constant when in equilibrium.

CHEMISTRY COMMUNITY

Search found 31 matches

Re: Instantaneous Rate

Re: Half life

Re: stoichiometric coefficients

Re: Achieve question 3, the sign of the rate of the reaction

Re: How do you know if its a first order reaction?

Re: Why zero order

Re: Explanation for battery signs

Balancing Reactions (achieve week 7&8 q3)

Re: n

Re: purpose?

Re: equilibrium do no work as ∆G = 0

Re: Delta H not vs delta H

Re: A temperature unit question

Re: Advice from a Medical Student [ENDORSED]

Re: What is residual entropy?

Re: Rusty on High School Chem [ENDORSED]

Constant Volume

Work on Systems

Work on Systems

Re: Open, Closed, Isolated System

Re: Questions about Step Up Sessions

Re: Step up Session worksheets

Re: Endothermic vs exothermic

Re: melting

Re: Exothermic Examples

Re: Exam Calculator Policy

Re: calculator

Re: midterm exam days

Re: How to find my posts

Re: Change in ICE Tables

Re: Q and K