Questions tagged [acid-base]

This tag should be applied to questions concerning acid and base reactions. An acid is capable of donating a hydron/ proton (Brønsted acid) or capable of forming a covalent bond with an electron pair (Lewis acid). A base on the other hand is a chemical species/ molecular entity having an available pair of electrons capable of forming a covalent bond with a hydron/ proton (Brønsted base) or with the vacant orbital of some other species (Lewis base).

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Acidic, Basic, and Neutral Medium

So I'm new to this concept and I can't find any proper explanation to this. What does it mean for a reaction to occur in an acidic, basic, or neutral medium?
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What is the maximum concentration of HNO3 (nitric acid) which may be handled outside of a hood?

Commercial stock solutions of HNO3 (nitric acid) are usually 70% w/w, and according to several MSDSs (e.g. here), it is dangerous to inhale it: Symptoms/effects after inhalation : Irritation ...
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What is the pH of a solution made by mixing 10.00 mL of 0.10 M acetic acid with 10.00 mL of 0.10 M KOH?

What is the pH of a solution made by mixing 10.00 mL of 0.10 M acetic acid with 10.00 mL of 0.10 M KOH? The $K_a =1.8 × 10^{-5}$ for $\ce{CH_3CO_2H}$. Assume that the volumes of the solutions are ...
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Why do nonmetal oxides react with water to form acidic compounds? [closed]

I am confused about the molecular basis by which nonmetal oxides react with water to form acidic compounds. For example, I understand that sulfur trioxide reacts with water to form sulfuric acid as ...
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Acid HClF6 and HIF6

I was wondering about $\ce{HClO4}$ which is a very strong acid . I thought it can be made stronger by replacing $\ce O$ with $\ce F$ to make $\ce{HClF6}$ but didn't find its existence . I thought that ...
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402 views

Is (Zn(OH)4)2- acidic or alkaline?

My chemistry teacher told me that $\ce{Al(OH)4^-}$, $\ce{Pb(OH)4^2-}$, $\ce{Zn(OH)4^2-}$ are called complex ions. So will they break down in some conditions and give out $\ce{OH-}$ to show alkaline ...
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What is the “coefficient of ionization” or “ionization coefficient”?

The question got bumped and I looked at it. The OP seems to use the two terms coefficient of ionization and ionization coefficient interchangeably and assigns the variable $\alpha$. The problem is in ...
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EQPt pH of a Monoprotic Acid-Base Titration: Product of Molarites Over Their Sum

Context The Henderson-Hasselbalch equation is as follows. $$pH=-\log\big(K_a\big)+\log\bigg(\frac{[A^-]}{[HA]}\bigg)$$ One may follow its derivation in order to understand how it came to be, yet ...
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How to calculate pH of the Na2CO3 solution given ambiguous Ka values

This is the exact question I faced on an exam. Calculate the pH of $\pu{0.05 M}\ \ce{Na2CO3}\ (\ce{H2CO3}: K_\mathrm{a,1}= 4\times 10^{-7},\ K_\mathrm{a,2}= 4.7\times 10^{-11})$ Solution $$\ce{Na2CO3 -...
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Predicting products of chemical equations? [duplicate]

Consider the equation $\ce{2 NaOH (aq) +Cl2 (g) —> NaOCl (aq) + NaCl (aq) + H2O (l)}$. How would one know the products of this reaction? Is there a general way of doing this? I would have no ...
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Calculating the pH of a solution of sodium carbonate

I've seen similar questions on this site, but I'm having trouble as my book said something else. For a $\pu{0.09989 M}$ solution of $\ce{Na2CO3}$, my book said: $$\ce{Na2CO3 + 2H2O -> H2CO3 + 2Na+ ...
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Comparing acidity of p-chloro benzoic acid and p-fluoro benzoic acid [duplicate]

I am really confused about comparing the acidity of p-chloro benzoic acid and p-fluoro benzoic acid. The question here doesn't have a conclusion and the discussion here is confusing. My Try: -F and ...
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Why will a strong base neutralize as much acid as a weak base?

I don't understand how the volume of 0.200 M NaOH needed to neutralize 250.0 mL of 0.010 M HCl (0.0125 mL) is the same volume of 0.200 M NH3 that would be needed to neutralize 250.0 mL of 0.010 M HCl.
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Understanding the increase in pH of a buffer solution upon incremental additions of NaOH analytically

So let's say we have $200\ \mathrm{mL}$ of $1\ \mathrm M$ $\ce{CH3COOH}$ solution. In this solution we have the equilibrium $\ce{CH3COOH <=> CH3COO- + H+}$. To that we add $100\ \mathrm{mL}$ of $...
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Gelatination of solution in saponification

When I performed a saponification experiment in school, I added some ethanol to the solution (glycerol ester fatty acid + sodium hydroxide) to change the equilibrium of the reaction. (Molecules of ...
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257 views

Weak acid dilution

Given a solution with molarity $\pu{0.5 M}$ of a weak acid $\ce{HA}$ has $\mathrm{pH} = 1.670$. How much water in liters needs to be added to $\pu{0.150 L}$ of the first solution to get a $\mathrm{pH} ...
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Formulation solubility?

Creatine is a popular sports/fitness supplement, generally sold as a powder to be mixed with water (usually like 5-10g creatine per serving). However, it is not very "soluble" in water -- barely 13.3g/...
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Can a used-up buffer solution be used again in the other direction?

Suppose a strong base is added into an acidic buffer (such as acetic acid buffer) up to the endpoint. This means that the acetic acid molecules neutralize the hydroxide ions to the point that the ...
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pH of ammonium acetate solution

I'm trying to calculate the pH of a 1M $\ce{NH_4CH_3COO}$. I know that I'll have these reactions: $\ce{NH_4CH_3COO <=> NH_4^+ + CH_3COO^-}$ $\ce{NH_4^+ <=> NH_3 + H^+}$ $\ce{CH_3COOH <=...
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Reaction of acids with water [duplicate]

Here is the reaction of $\ce{HCl}$ with $\ce{H_{2}O}$ I found on a website $$\ce{HCl + H_{2}O -> H^{+}(aq) + Cl^{-}}(aq)$$ However, in my text-book, the reaction is given as $$\ce{HCl + H_{2}O ...
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Which of these functional groups is soluble in aqueous HCl and/or NaOH?

http://pastpapers.papacambridge.com/view.php?id=Cambridge%20International%20Examinations%20%28CIE%29/AS%20and%20A%20Level/Chemistry%20%289701%29/2015%20Jun/9701_s15_qp_42.pdf I need some help to ...
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Why titrating strong base with weak acid doesn't end at pH 7? [duplicate]

If I understand this titration correctly, if we titrated 50mL 1.00M acetic acid with 1.00M NaOH, the equivalence point would happen at a pH greater than 7, and less than 50mL of NaOH would need to be ...
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148 views

Ignoring initial H+ Concentration For Addition of Strong Base to a Buffer Solution

When adding a strong base to a buffer solution, with a generic weak acid HA and generic weak conjugate base A-, is the initial amount of H+ ignored because it is so small? Specifically, at least in my ...
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Theoritical amount of Sodium Bicarbonate

I have to find the theoretical amount of sodium bicarbonate. The steps I followed in order to produce it are: 15g $\ce{NaCl}$ are added to a beaker. Then we add 87.5 mL of $\ce{NH3}(12M)$ We add 115g ...
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1answer
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Why isn't ammonium strong acid, since it's charged and ammonia is neutral? [duplicate]

Why is ammonium such a weak acid $(\mathrm pK_\mathrm a = 9.24)$, if $\ce{NH4+}$ has a positive charge on nitrogen, while $\ce{NH3}$ is neutral. It means that conjugate base (ammonia) is really stable,...
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Why does the hydrogen atom in HCl (when dissociated in water) bond to the oxygen rather than staying with the chlorine atom?

Why does the hydrogen atom in $\ce{HCl}$ (when dissociated in water) bond to the oxygen rather than staying with the chlorine atom. They ($\ce{Cl}$ and $\ce{O}$) have roughly the same ...
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What happens to acids/bases left out overnight?

I conducted a titration experiment a few days back and was unable to neutralize the solution in time, so I had to leave the solutions of HCl and NaOH out overnight in order to use them the next day. ...
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Calculation of proportion of zwitterion from this please. [closed]

This is the question. I tried to post it in the title section but it was rejected because it was considered lengthy. Question: Valine is one of the 20 natural amino acids and has an acid -COOH (pka1=2....
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pH(H3O+ ion concentration) of a mixture of 2 weak acids

I need to find out the $\ce{H3O+}$ ion concentration in a mixture of 2 weak acids $\ce{HA1}$ and $\ce{HA2}$. They will be ionised as $$\ce{HA1 + H2O <=> A1- + H3O+}$$ And $$\ce{HA2 + H2O <=&...
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How can you change the proportions of reactants and products at equilibrium if Le Chatelier's principle is occurring?

For example, how could you make a buffer with equal concentrations of acid and conjugate base? If you add more conjugate base, it will shift the equilibrium to form more acid, which will keep the ...
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knowing that a strong base is a strong electrolyte, when we add a weak acid in water, will its conjugate strong base be a strong electrolyte too?

I am not sure if the questions makes sense. What i am trying to say is that, if weak acids form strong conjugate bases, why aren't they strong electrolytes? Thank you in advance.
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Acidic strength of organic acids. Substituted PhCOOH acids

Could someone please explain the order of acidity of ortho, para and meta substituted benzoic acids with the substituent as methyl group? Methyl group operates +I and +R effect, I believe.
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How to determine the hydroxide ion concentration in an acidic aqueous solution?

When doing a titration with $\ce{HCl}$ and $\ce{NaOH}$, both being strong and dissociating completely, if you add a volume of $\ce{NaOH}$ that is less than needed to reach the equivalence point, you ...
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Why in -COOH group the C atom pulls electron cloud from the OH group O where as the double bonded O pulls the electron cloud towards itself?

Should both the oxygen pull the cloud as O is more electronegative than C . I think that as the cloud density decreases near carbon therefore it pulls . A proper explanation please .
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Why methanoic acid is more acidic than phenol? [duplicate]

If you draw the resonatic structure, obviously, the conjugate base of phenol seems to be more stabilized than methanoic acid's. Then why this anomaly?
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pH-dependency of the acidic dissociation of carbonic acid

I know the product of $\ce{CO2 +H2O}$ yields $\ce{H2CO3}$. This is a reversible equation so $\ce{H2CO3}$ goes back to $\ce{H2O + CO2}$. However, my question is: Is there a certain pH which will ...
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What do you call acids that can disassociate more than 1 H+

What do you call acids that can disassociate more than 1 H+? Is it like Class n acids for acids that can disassociate n H+?
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Why anions of weak acids are weak bases? [duplicate]

This is what I saw from Chemistry: The Central Science 13th ed. by Theodore brown, page 698. It stated that there are two types of weak bases: one is those with lone pairs of electron and the other is ...
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1answer
462 views

Nucleophilicity vs Basicity [duplicate]

Can something be both a nucleophile and a brønsted base? Also , I'm actually quite confused about the difference between these two terms.
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Titration of hydrochloric acid with sodium hydroxide

I have a question regarding titration of hydrochloric acid with sodium hydroxide. Assume you have a solution of NaOH with pH = 12. With this NaOH you titrate a HCl solution. Then, will the pH of the ...
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Dissociation constants of oxalic acid

For oxalic acid, $\mathrm{K}_{\rm a1}> \mathrm{K}_{\rm a2}$. My teacher told me that after first deprotonation, $\ce{COO-}$ acts as an electron donating group and hence reduces the acidic ...
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what is the reaction between copper and an acid [duplicate]

what happens when copper is reacted with hydrochloric acid may be dilute or concentrated.Should it displace hydrogen?if not what will happen if yes why?i think it will not react because copper is ...
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46 views

what makes an acid a strong acid or weak acid? [duplicate]

When my teacher referenced nitric acid as a strong acid, I thought it was strong because it donates more than one H+ per molecule, but then I saw the equation is $\ce{HNO_3}$ and it only donates one. ...
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45 views

When do one have to actually calculate the net charge of an amino acid? [duplicate]

When the pH and the pKa levels differ by 2 or more you don't need to calculate the net charge. What you do then is to just count the negative and positive charge and add them up. When pH=pKa you also ...
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acids, bases, salts, etc

All the chemical compounds can be categorized as acids, bases, and neutral compounds. There are different theories, namely Arrhenius Theory, Brønsted-Lowry Theory, Lewis Theory, which define the acids ...
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The reason for bicarbonate acting as a buffer

My question is: what is the primary reason that bicarbonate ($\ce{HCO3^-}$) can act as a buffer in a solution? The two (possibly) relevant equations that I can think of are $$ \ce {H2CO3 + H2O <=&...
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1answer
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Why is Ma*Va=Mb*Vb still valid for weak acids/bases? [duplicate]

I asked my chemistry teacher this today and didn't get an answer. It would seem to me that the equation for determining the morality of the unknown in a titration, MaVa = MbVb, would only work if the ...
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1answer
547 views

Acids / Bases - Need some clarity for final exam [closed]

I'm studying for my final exam, and these are the questions I got wrong on the mid term, could anyone help correct me? I know people are against giving answers for homework, so I must add that is now ...
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1answer
25 views

carbon dioxide and its behaviour in acid base balance [closed]

In human body acid base balance, why and how does the dissolved carbon dioxide increases the hydrogen ion concentration with increasing in its partial pressure..? At the same time bicarbonate ion is ...
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1answer
106 views

Calculating pH of reaction mixture of silver nitrate and ascorbic acid

I am designing an experiment but before I do, I wanted to understand if the following method is right to calculate the expected $\mathrm{pH}$ when I mix $\pu{0.736 M}$ $\ce{AgNO3}$ and $\ce{C6H8O6}$. ...

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