Acids and Bases

[Karissa_Lee_1A]

How can you tell if a compound is acidic or basic?

For regular compounds you would need to calculate the pH. For salts, there's a list of strong acids and bases that you can use. If the salt is made up of a strong base and weak acid the salt is basic; if the salt has a strong acid and weak base the salt is acidic; if there is a strong base and a strong acid the salt is neutral.

[bella moore]

What is the relationship between pKa and pH? This was a question on the homework, and I just wanted a little more help.

[bella moore]

You can tell if a compound is acidic if it tends to give away an H+, and if it's basic, it tends to accept an H+.

[Ryan Shelburne 3D]

How do we differentiate between strong and weak Acids on a subatomic level (ie: electrons)?

[Ryan Shelburne 3D]

Amphiprotic refers to compounds that can act as either an acid or a base.

[Ryan Shelburne 3D]

What's the relationship between the molarity of a strong base and it pOH?

[Ryan Shelburne 3D]

What happens to the end concentration of strong acids and bases after dissociation?

[Ryan Shelburne 3D]

How do you know if a compound is involved the initial or secondary reaction? (ie: salt and buffer problems)

[Ryan Shelburne 3D]

Do we have to convert pressure to mmHg, torr, or atm when doing concentration / equilibrium equations?

[Ali Nosseir]

In most cases, if the K1 value is greater than the K2 value, you only use the first reaction to calculate whatever is asked. This is because if the K2 value is smaller, the amount of H+ or OH- ions it creates from the reaction is so small that it barely affects the pH.

[Ryan Shelburne 3D]

Will exothermic reactions favor products or reactants and why?

[Ryan Shelburne 3D]

What does it mean when an acid is a donor?

[Ryan Shelburne 3D]

Why does temperature affect equilibrium constant but not pressure?

[Ryan Shelburne 3D]

What's the easiest way to memorize strong acids and bases?

[Ryan Shelburne 3D]

Why do strong acids yield weak conjugate bases?

[805737147]

I just had a quick question about conjugate acids and bases. I just wanted to know how we know which compound is the conjugate acid/base in the chemical reaction and also how this concept may come up when solving problems?

An acid is a proton donor and a base is a proton acceptor. An acid always has a conjugate base and a base has a conjugate acid. So, if we see something like CH3COOH, we know it's an acid and it has a conjugate base on the other side of the reaction. Sometimes, a question will give you the Kb of a conjugate base and you have work backwards. Hope this helps!

[805737147]

Why do strong acids yield weak conjugate bases?

A strong acid means it will disassociate and very easily donate a proton. That means that it's conjugate base doesn't really have a reason to re-accept another proton. Since it won't easily accept a proton, a strong acid yields a weak conjugate base. (weak = won't easily accept a proton). Similarly, if you consider a super strong base, they will accept a proton and hold onto it really tightly. Therefore, there's no reason for it's conjugate acid to donate it a proton.

[805737147]

Will exothermic reactions favor products or reactants and why?

An exothermic reaction has an overall negative change in enthalpy (- change in H). That means when heat is added, it will favor the reactants.

An endothermic reaction naturally produces a net positive change in enthalpy. That means when you add heat, the reaction will utilize Le Chatelier's Principle and try to minimize the change. So, the increase in heat causes the reaction to shift to favor the products, therefore giving off heat.

[Grace M Miller 1K]

Why are we using [H3O] instead of H+ ? What's the difference? Which one does pH really measure?

[Grace M Miller 1K]

How do we write dissociation reactions? It seems to me like there are multiple ways to write them and I often get it wrong.

[306022612]

Does anyone know if we have to memorize strong acids and bases or will it be provided for us?

My suggestion would be to memorize it in terms of groups. Acids, that are similar, and bases, that are similar. A lot have shared commonalities and that helps!

[306022612]

Why are we using [H3O] instead of H+ ? What's the difference? Which one does pH really measure?

H+ does not really exist in real life. We use it as an example or as something to make a point. But, in reality, hydronium is the only thing that exists.

[306022612]

Why are we using [H3O] instead of H+ ? What's the difference? Which one does pH really measure?

H+ does not really exist in real life. We use it as an example or as something to make a point. But, in reality, hydronium is the only thing that exists.

[SameeraGurram1]

How can you tell if a compound is acidic or basic?

To tell if a compound is an acid or a base, you should just count the hydrogens on each compound before and after a chemical reaction occurs. If the number of hydrogens decreases, the compound is an acid because it donates its hydrogen ions. If the number of hydrogens increases in the compounds, then it is a base because it accepts hydrogen ions. Generally, basic compounds have hydroxide ions too. Hope that helps!

[Alyssa Gates 1H]

This may be a dumb question, but other than knowing the strong bases and strong acids how can we know what is a base and what is an acid?

[905988526]

How can you tell if a compound is acidic or basic?

I like to think that most compounds that start with H (except H20 for obvious reasons) are on the acidic side. Most that have NA are basic, and the neutral ones can be accounted for if the elements in the compound would "cancel each other out" such as one acidic and one basic element forming a compound. Besides that it is mostly just memorization!

[Akilah Beatty 2k]

Group 1 and group 2 on the periodic table consist of the bases.

[Annabelle_Wilson_1E]

It can be hard to tell what compound is an acid/base by looking at it. Typically compounds with a H are acids and ones with OH are baes but this is not always the case. You need to look at the full chemical equation and see if it donates a hydrogen ion (acid) or accepts one (base).

[Annabelle_Wilson_1E]

It can be hard to tell what compound is an acid/base by looking at it. Typically compounds with a H are acids and ones with OH are baes but this is not always the case. You need to look at the full chemical equation and see if it donates a hydrogen ion (acid) or accepts one (base).

[Itxhel Jimenez 1B]

This may be a dumb question, but other than knowing the strong bases and strong acids how can we know what is a base and what is an acid?

Hi Alyssa, that is a completely reasonable question! Usually what I do is look at the molecule. If it has an H in the front in is an acid. If it doesn't it may be a base.

[Itxhel Jimenez 1B]

Hi I was wondering what the difference is between a bronsted acid/base and a lewis acid/base. Thanks

[Abigail S 2C]

Where do we find the answers to the recommended practice questions from the book?

I believe they’re on a separate document found under welcome and get started under chemical principles student solutions

[Abigail S 2C]

Group 1 and group 2 on the periodic table consist of the bases.

Is there a specific name for these types of bases on the periodic table?

[606026147]

There are not videos on the chemistry community, but I find the section in the textbook on Acids and Bases. The textbook problems also really help.

[Levon_Avedian_2H]

How do Acids and Bases relate to K and the concentration gradient of products and reactants?

[Saahithi Kari]

If the equation is doesn't include a strong acid or base and we therefore cannot assume it completely dissociates, what do we do?

You would use an ice table and solve using a quadratic function as we did for the chemical equilibrium problems. You essentially follow the same steps, you would just need to be able to identify if the reactant is an acid or base to know if the product dissociates to H3O+ or OH-, and then solve for their respective concentrations.

[Saahithi Kari]

Why are we using [H3O] instead of H+ ? What's the difference? Which one does pH really measure?

It's because H+ itself does not actually exist, but rather H3O+ because they are in an aqueous environment. pH is just measuring the hydronium ion concentration, and they are interchangeable, but H3O+ is just more accurate.

[Saahithi Kari]

Group 1 and group 2 on the periodic table consist of the bases.

Is there a specific name for these types of bases on the periodic table?

I don't think there is a specific name for these bases that we need to be aware of, just that generally group 1 and group 2 hydroxides are strong bases.

[Grace M Miller 1K]

Why are we using [H3O] instead of H+ ? What's the difference? Which one does pH really measure?

It's because H+ itself does not actually exist, but rather H3O+ because they are in an aqueous environment. pH is just measuring the hydronium ion concentration, and they are interchangeable, but H3O+ is just more accurate.

Oh my gosh, high school chemistry lied to us all.

[106024424]

Is there any pneumonics that can help you remember the strong acids and bases?

[Luke Smith]

What is the conjugate seesaw exactly? And what do we do when it is in a reaction?

The conjugate seesaw refers to what happens when you react an acid or base with water. For example, if you react a strong acid with water it will produce a weak base. The same goes for if you were to react a strong base with water, you would produce a weak acid.

[Grace M Miller 1K]

Is there any pneumonics that can help you remember the strong acids and bases?

Strong Acids:
So I brought no clean clothes
H2SO4, HI HBrought HNO3 HClean HCl04thes
H2SO4 (sulfuric acid)
HI (hydrologic acid)
HBr (hydrobromic acid)
HNO3 (nitric acid)
HCl (hydrochloric acid)
HClO4 (perchloric acid).

And a more graphic one for Strong Bases:
Little Nannies Kill Rabbits Causing Carnivorous Screaming Babies
LiOH
NaOH
KOH
RbOH
CsOH
Ca(OH)2
Sr(OH)2
Ba(OH)2

[205756817]

Yes there will be a section and the professor sent out an email for it

[105944027]

This is the response to someone who asked what is an acid and a base. So basically, everything that contributes an H+ (proton) is an acid, while anything that accepts an H+ is a base (proton). A lot of the acids are distinguished from bases by having a H in front of them. Hope this helped!

[105944027]

Is there any pneumonics that can help you remember the strong acids and bases?

Strong Acids:
So I brought no clean clothes
H2SO4, HI HBrought HNO3 HClean HCl04thes
H2SO4 (sulfuric acid)
HI (hydrologic acid)
HBr (hydrobromic acid)
HNO3 (nitric acid)
HCl (hydrochloric acid)
HClO4 (perchloric acid).

And a more graphic one for Strong Bases:
Little Nannies Kill Rabbits Causing Carnivorous Screaming Babies
LiOH
NaOH
KOH
RbOH
CsOH
Ca(OH)2
Sr(OH)2
Ba(OH)2

I just wanted to say thank to whoever posted this! This actually helps a lot! Thank you!

[Levon_Avedian_2H]

How do acids and bases relate to this equation: pKw = pH + pOH = 14 at 25(degrees c)?

[405672459]

There should be a list with both acids and bases posted on chemistry community. If you go up to the right hand corner and type in the key words acids and bases the worksheet with a list of acids and bases should appear.

[Grace M Miller 1K]

How do acids and bases relate to this equation: pKw = pH + pOH = 14 at 25(degrees c)?

pH and pOH are measures of acidity and basicity! :)

[jadyndavidson]

Determining whether or not a compound is acidic or basic is typically based on memorization. However, if you are trying to figure out whether a salt compound is acidic, basic, or neutral is based on whether the salt contains conjugate acids and bases of weak acids and bases. If the salt contains a conjugate aid of a weak base, it will produce acidic aqueous solutions. If the salt contains a conjugate base of a weak acid it will produce basic aqueous solutions. The conjugate acids and bases of strong acids and bases do not effect pH because they are considered spectator ions.

[Sydney_Hoang_Dis1B]

How can you tell if a compound is acidic or basic?

If there is a a H+ in front and the charge of the other end of the compound is negative, then it is usually an acid. On the other hand, there will be an OH- attached to positive charges side, then it is likely a base.

[LianaHernandez1F]

To determine if a compound is acidic or basic: Count the hydrogens on each component before and after the reaction to determine if it is an acid or a basic. If there are fewer hydrogens, then the substance is acid (donates hydrogen ions). The material is the base if the hydrogen count has increased (accepts hydrogen ions).

[LianaHernandez1F]

I just had a quick question about conjugate acids and bases. I just wanted to know how we know which compound is the conjugate acid/base in the chemical reaction and also how this concept may come up when solving problems?

The conjugate base is the acid minus its proton. A strong acid is completely dissociated in water while a weak acid is in equilibrium with its conjugate base in water. This concept is important in questions when it is asking you to solve an acid/base reaction. Often times you will need to complete the reaction and also know when to use H+ or H- when looking at formulas.

[LianaHernandez1F]

If a temperature is not given, can we assume we are solving at 25 degrees celcius?

If temperature is not given it means it usually does not have an effect on the equation you are solving for. You could assume 25 Celsius since that is standard but I would definitely make sure that the equation does not ask for or use temperature. In this case you may need to save for temp.

[306060519]

Is there a section for Acids and Bases on the 14B Chemistry Community section?

Yes, you need to read the forum guide and it will show you the way.

[306060519]

Is there a section for Acids and Bases on the 14B Chemistry Community section?

Yes, you need to read the forum guide and it will show you the way.

[Ellen Lozada 3L]

I just had a quick question about conjugate acids and bases. I just wanted to know how we know which compound is the conjugate acid/base in the chemical reaction and also how this concept may come up when solving problems?

The concept of conjugate acids and bases is essential in acid-base chemistry and helps us understand how substances can donate or accept protons (H+ ions) in chemical reactions. To determine which compound is the conjugate acid or base in a reaction, there are some general guidelines:

Identify the Initial Acid and Base:
Start by identifying the initial acid and base in the chemical reaction. The acid is a substance that donates a proton (H+), while the base is a substance that accepts a proton.
Determine the Products:
Determine the products of the reaction. When an acid donates a proton, it forms a conjugate base. When a base accepts a proton, it forms a conjugate acid.
Compare with the Initial Species:
Compare the products with the initial species. The species that gains a proton compared to the initial species is the conjugate acid, and the species that loses a proton compared to the initial species is the conjugate base.

[Baria Alaswad 2E]

How can you tell if a compound is acidic or basic?

Formula Clues:
Starts with 'H' → Likely acid (e.g., HCl).
Ends with '-OH' → Likely base (e.g.,NaOH).

PH:
Below 7 = Acidic.
Above 7 = Basic.

Litmus Test:
Acid turns blue paper red.
Base turns red paper blue.

Reactions:
Acids often fizz with metals.
Bases feel slippery.

[705721552]

Are acids and bases going to be featured on the midterm.

[705721552]

Khan academy has a very detailed video on understanding acids and bases.

[705721552]

Khan academy has a very detailed video on understanding acids and bases.

[Bethel Tesfamicael]

How can you tell if a compound is acidic or basic?

You can determine if a compound is acidic by testing its pH. If the pH is less than 7, it's acidic. If the pH is greater than 7, it's basic

[205991792]

When placing compounds from least acidic to most acidic. Is it sufficient enough to look at which compound has the weakest bond- thus most acidic? Or is there a more efficient and accurate way to place them in the order?

[Alvin Au]

Determining the gradient of acids' strength can take multiple methods, but the most efficient method is always subjective. While your method is one of them and something I also use myself, you could try looking into these other methods to see if they're easier for you: stability of the conjugate base, electronegativity of the atom bearing the acidic hydrogen, inductive effects, resonance effects.

[Serena 1B]

The way you can tell the difference between acids and bases in an equation, is by looking for H+ at the beginning of a chemical formula because then it is acidic since acids donate a proton, while bases have an OH- at the end of their chemical formulas since bases accept a proton.

[Ashley Barrera 1J]

Do we need to memorize certain acids or bases or will we be told whether or not it is a strong acid or base?

I believe Professor Lavelle mentioned as review in case we didn't come into the course with much strong retention of this information, along with the log scales. I do believe we are expected to have a good idea about the concepts of strong acids before he teaches us about weak acids. Its best to try to know as best you can memorize in case we do get a curveball of not being given information in a test question.