Skip to main content

Questions tagged [concentration]

The concentration characterizes the composition of a mixture with respect to the volume of the mixture. There are mass, amount, number and volume concentrations. Related and within the scope of this tag are normality, molality, mole fraction/ratio, mass fraction/ratio.

Filter by
Sorted by
Tagged with
2 votes
1 answer
246 views

Electronic oxygen concentration sensor

I bought an electronic meter which measures the concentration of oxygen in air. But I think the sensor has failed because it is too old, as it had a crusty substance coming from it.but I can no longer ...
Jodes's user avatar
  • 461
1 vote
0 answers
275 views

Co49Ni21Ga30 - molar mass and density

I need to calculate the molar mass and density of the shape memory alloy $\ce{Co49Ni21Ga30}$ (I suppose the numbers indicate the mass percentage). To get the molar mass, is it correct to use the ...
randomal's user avatar
  • 119
3 votes
1 answer
477 views

Osmolarity and osmotic pressure

You have discovered a new strain of bacteria called Tankeromyces subtilis that has a special outer membrane that is capable of withstanding high levels of osmotic pressure. These bacteria can survive ...
Michael's user avatar
  • 43
7 votes
1 answer
11k views

How to calculate the concentration based on dilution of a stock solution?

One of my exam questions is about lipstick and calculating the amount of lithium in the lipstick by AAS. The determination took place by making standard solutions with known concentrations of lithium. ...
Shaggy's user avatar
  • 87
4 votes
1 answer
129 views

Why is the concentration halved at the intersection of Hg²⁺/Hg₂²⁺?

For the couple $\ce{Hg^2+}/\ce{Hg2^2+}$: $E^\circ = \pu{0.91V}$. At the border the concentration is $c = \pu{0.10 mol \cdot L-1}$ for all ions. Hence build the stability diagram of mercury. I have: ...
ParaH2's user avatar
  • 4,207
7 votes
2 answers
4k views

Alkaline glycine buffer molarity

Having never prepared a buffer solution before, I am hoping for a little help in understanding the process. This method I plan to use calls for a $\pu{0.1M}$ glycine buffer at pH $10.6$. Some ...
Franklin P Combs's user avatar
-3 votes
1 answer
650 views

How to calculate an equilibrium constant from concentrations and a reaction equation [closed]

2.50 mL of 0.0150 M A, 3.50 mL of 0.0250 M B, and 4.00 mL of distilled water were added to a 50-mL beaker. At equilibrium the concentration of C is 2.05*10^-3M at 25degrees celsius. Calculate Kc for ...
Sage's user avatar
  • 9
1 vote
0 answers
131 views

What is the equation that demonstrates the relationship between molar conductivity and temperature?

Can someone please help me find the equation that defines the relation between molar conductivity and temperature. I have found some information, but it was not really that much complete.
Débora Eiriz's user avatar
3 votes
3 answers
8k views

Finding is the concentration of H⁺ in a benzoate buffer solution after adding HCl

Q: A buffer with a $\mathrm{pH}$ of 4.44 contains $\pu{0.21 M}$ of sodium benzoate and $\pu{0.12 M}$ of benzoic acid. What is the concentration of $\ce{[H+]}$ in the solution after the addition of $\...
chemstudent's user avatar
0 votes
0 answers
750 views

Concentration cell lower half cell concentration from measured cell potential

I am trying to find the Ksp of silver thiocyanate: AgSCN(s) --> Ag+ (aq)SCN-(aq) but I need to first prove that the lower [Ag+] = 1.27-12 M, but don't know how to find it. The data I am given: ...
Zebundi's user avatar
3 votes
1 answer
90 views

Amount of substance of a molecule in a solute the same as amount of substance of constituent elements?

I’ve done absolutely no chemistry since high school. Now, 16 years later, I’ve been asked to look at some chemical analyses and I’m having trouble! Context: I’ve got a series of spectroscopy ...
Dai's user avatar
  • 131
2 votes
3 answers
153 views

Can you find [SO₃²⁻] with just the two acid dissociation constants Kₐ₁ and Kₐ₂?

Sulfurous acid, $\ce{H2SO3}$, is a diprotic acid. \begin{align} K_{a1} &= 1.6 \cdot 10^{-2}\\ K_{a2} &= 6.4 \cdot 10^{-8}\\ \end{align} Is it possible to find the concentration of $\ce{SO3^2-}...
user1561772's user avatar
5 votes
2 answers
327 views

NaClO Concentration

In my previous occupation the usage of bleach--$NaClO$--I found was quite staggering, and based off of the health issues that I and other coworkers were having, I wanted to see how close we were ...
Doryan Miller's user avatar
6 votes
1 answer
868 views

Representing woody biomass concentration for kinetic reactions

Woody biomass is composed of cellulose, hemicellulose, and lignin components. The following diagram provides representative formulas for each component: Biomass can be represented by it's density, ...
wigging's user avatar
  • 299
2 votes
2 answers
8k views

Determine molecular weight of biomass based on ultimate analysis [duplicate]

The ultimate analysis (by weight percent) for beech wood is: $$\ce{C}=49.05\,\%,\; \ce{H}=5.83\,\%,\; \ce{O}=45\,\%,\; \ce{N}=0.12\,\%$$ Using the ultimate analysis values, the molar mass of each ...
wigging's user avatar
  • 299
2 votes
1 answer
5k views

How many moles NH4Cl must be added to NH3 to create buffer with pH=9?

How many moles of $\ce{NH4Cl}$ must be added to $\pu{2.0 L}$ of $\pu{0.10 M}$ $\ce{NH3}$ to form a buffer with $\mathrm{pH}=9$? Assume the addition does not change the volume of the solution ...
math_lover's user avatar
  • 1,398
0 votes
1 answer
3k views

Experimental difficulty with the iodine clock reaction

I did the iodine clock reaction using sodium metabisulfite and potassium iodate. As I understand it, increasing concentration is supposed to speed up your reaction rate. I did 10 trials. The first 5 I ...
mcchem's user avatar
  • 19
5 votes
1 answer
151 views

What is the minimum number of given sets of information required to complete an ICE chart for an equilibrium reaction?

I'm considering creating a program that automatically completes an ICE chart/table when the minimum given information is provided. The reason I'm posting my question here is because I need to know the ...
Joe's user avatar
  • 51
4 votes
1 answer
963 views

Calculate species concentration from first-order kinetic reactions

I am trying to determine the concentration of products from the kinetic reactions of wood pyrolysis. The kinetic scheme separates the wood into cellulose, hemicellulose, and lignin. For example, the ...
wigging's user avatar
  • 299
2 votes
2 answers
47k views

Finding new pH after NaOH added to buffer solution

I have a buffer containing 0.2 M of the acid $\ce{HA}$, and 0.15 M of its conjugate base $\ce{A-}$, with a pH of 3.35. I need to find the pH after 0.0015 mol of $\ce{NaOH}$ is added to 0.5 L of the ...
Caesium-133's user avatar
1 vote
0 answers
131 views

Determining [CO2] of a sample in ppm

I have 20mL gas samples and I need to determine the [CO2] in ppm. I have a Li-Cor 6200 with a closed loop, so essentially I will inject a volume of gas into the loop and the change in the output is ...
suffering-grad's user avatar
1 vote
0 answers
80 views

How to calculate concentration of hydrogel nanoparticles [closed]

I have prepared hydrogel nanoparticles in aqueous solution. How to calculate concentration of hydrogel nanoparticles ?
aparna chaudhary's user avatar
3 votes
1 answer
25k views

Molarity vs Normality in labeling sulfuric acid

Molarity (M) is defined as moles of solute per liter of solution while Normality (N) is defined as moles of reacting units per liter of solution. Most texts use sulfuric acid as an example to ...
tgs's user avatar
  • 31
1 vote
0 answers
62 views

Estimating the protein concentration of an unpure protein solution

I'm confused on this problem for estimating protein concentration. Upon first glance, it looks like a simple Beer's law problem. but then there's the issue that the protein is not pure. How do I ...
John Snow's user avatar
  • 4,535
2 votes
1 answer
109 views

Finding equilibrium concentrations, trouble simplifying equation

For $\ce{CO (g) + H2 (g) <=> CH2O (g)}$ with Kc = 0.068 @ 273K initial concentrations being $\ce{[CO]}$ = 1.25M, $\ce{[H2]}$ = 2.00M, $\ce{[CH2O]}$ = 1.00M I did $\frac{1.00}{((1.25)(2.00)} = ...
Caesium-133's user avatar
0 votes
1 answer
3k views

Finding Kp at another temp with /\Hrxn [closed]

Took a pic of the paper I tried it on it on, has the exact problem description written at top, and what I tried. Figured that would be easier then typing all that. The answer is supposed to be 2.0.
Caesium-133's user avatar
1 vote
2 answers
92 views

Concentration Inquiry

I just found a random example so I could highlight my inquiry: A chemist wants to make .5L of a 20M solutionusing $\ce{NaOH}$. The solution will be made from solid $\ce{NaOH}$ and water. How many ...
user avatar
3 votes
1 answer
2k views

How to calculate the concentration of NO at equilibrium?

$\ce{N2(g) + O2(g) <=> 2NO(g)}$, $K_c = 4.1 \cdot 10^{-4} (T=2000~^\circ\mathrm{C})$ What is $\ce{[NO]}$ when a mixture of $0.20~\mathrm{mol}$ $\ce{N2(g)}$ and $0.15~\mathrm{mol}$ $\ce{O2(g)}$ ...
Caesium-133's user avatar
3 votes
1 answer
138 views

How can inconsistencies in these sodium chloride solutions be explained?

I'm entirely chemically-naive and am confounded when trying to convert $\ce{NaCl}$ brine concentrations to moles per litre. The situation is that I'm performing linear multiple regressions using ...
lithic's user avatar
  • 133
5 votes
2 answers
13k views

Whose concentration is more 1 molar or 1 molal?

I was reading about concentration terms like molarity, molality, etc. and then I came across a question: which concentration is more: 1M(molar) of solute x dissolved in water vs. 1m(molal) of solute ...
5cube's user avatar
  • 125
2 votes
1 answer
2k views

How can I calculate molality from molarity?

How can we determine the boiling point of 1 molar aqueous solution (density 1.06 g per ml) of KBr? If I use the colligative property formula than I require molality instead of molarity. Here the ...
5cube's user avatar
  • 125
0 votes
1 answer
123 views

Confused on normallity

So normality is 'equivalents' over liters solution right? I'm having a hard time understanding exactly what an equivalent is. At first from one thing I read i thought it was just the H released from ...
Caesium-133's user avatar
2 votes
1 answer
11k views

Calculating the concentration of acetic acid in vinegar from pH

DavePhD was kindly helping me with this problem but the site indicated the discussion had gone on too long. Calculating vinegar strength I don't have enough units to start a chat so I am starting a ...
VinegrMan's user avatar
1 vote
1 answer
19k views

How can n = c/v?

I know this question is probably really rudimentary or I may just be fundamentally misunderstanding something but I would really like to just understand this. So $n=\pu{1 mole}$, $c=\pu{1 moles/L}$ ...
Paze's user avatar
  • 703
1 vote
1 answer
475 views

How do I utilize Henry's Law Constant?

I have tried for several hours to answer this question with no luck. I believe I may be missing a couple of steps or I am not utilizing the given information properly. Nonetheless, some guidance will ...
Cetshwayo's user avatar
  • 294
0 votes
2 answers
473 views

Methylene blue used as funguscide in cichlid reproduction - concentration measurement?

I have an aqueous solution of methylene blue. How do I determine the concentration of this solution, so I can duplicate it?
DANNY HATCHER's user avatar
4 votes
1 answer
407 views

How to calculate the parts-per-million concentration from a percent concentration?

I am asked to find the concentration of magnesium ions in ppm for a $0.025\ \%$ solution of $\ce{MgCl2}$. I can use this formula: $$\text{concentration in ppm} = \frac{\text{mass solute}_\mathrm{(g)}}{...
Caesium-133's user avatar
2 votes
1 answer
1k views

Ion concentration in acid and base

Hello here is a question that is a bit confusing I hope you can help me solve it and understand it: Determine the hydronium and hydroxide ion concentrations in a solution that is $10^{-4} M \ce{...
Mariam's user avatar
  • 23
-5 votes
1 answer
2k views

Mass of "orange" in 25% orange juice [closed]

Hypothetical question: Knowing that orange juice has 25% concentration of orange. And knowing mass of juice which is 200g. What ...
changtung's user avatar
0 votes
0 answers
151 views

How could click reaction take place at low concentration?

I have DBCO-functionalized resin, and the DBCO group is validated with FAM-azide. But I cannot use this resin to react with FAM-Azide-labled primer, which has very low concentration (20 μM, it is ...
leetom's user avatar
  • 149
2 votes
0 answers
65 views

Preparing CdSe electrodeposition bath

What is the best way of preparing an aqueous solution containing 5 mM $\ce{CdSO4}$, 1 mM $\ce{SeO2}$, 0.5 M $\ce{Na2SO4}$ and adjusting pH to 3 by adding 0.5 M $\ce{H2SO4}$? What is the ...
Mirette's user avatar
  • 21
2 votes
2 answers
2k views

Heat energy of phosphoric acid evaporation

Looking at a system in which phosphoric acid is concentrated in an evaporator which uses a constant recycle stream with a heat exchanger in this stream to heat the acid so that water evaporates out of ...
Samantha's user avatar
3 votes
2 answers
2k views

Find amount of acid and base required to make buffer

I am wondering if it is possible to know exact amount of acid and base that we can put in together to make a buffer. I want to make a 0.05 M extraction buffer using disodium hydrogen phosphate (DHP) ...
drgenetix's user avatar
2 votes
2 answers
2k views

Are all strong acids the same strength?

Since the six strong acids dissociate completely into their ions, and the reaction goes to completion, does this mean that acids such as $\ce{HI}$ and $\ce{HCl}$ have the same acidic strength? I know ...
McB's user avatar
  • 377
6 votes
1 answer
4k views

How to interpret the instruction of the dilution of hydrogen peroxide?

I am required to prepare $\pu{120cm3}$ of hydrogen peroxide to each of one of my students tomorrow. Some material is given to me on the method of preparing the solutions. Within the method of ...
abdelmoniem's user avatar
0 votes
5 answers
26k views

Does the water in hydrates affect final concentration?

Say I have a hydrate, and I am going to dissolve it in water. Does the water in the hydrate affect the final concentration? Here's an example: If I have $\pu{249.69 g}$ of $\ce{CuSO4·5H2O}$, and ...
pjrader1's user avatar
  • 181
12 votes
1 answer
65k views

Does concentration of salt increase or decrease rate of rusting?

I want to know whether increasing the concentration of salt, specifically $\ce{NaCl}$, increases or decreases the rate of rusting. There are conflicting theories that explain opposite outcomes: ...
Tejas Ramdas's user avatar
1 vote
1 answer
3k views

How to explain the increase in current with the increase in the concentration of responsible ions?

I have conducted an experiment wherein I have used different concentrations of $\ce{H2SO4}$, $\ce{HNO3}$ and $\ce{H3PO4}$ as the electrolytes. I filled the acid in glass tube and used a 9V battery, ...
nick's user avatar
  • 21
1 vote
1 answer
4k views

Molality of solution having more than one solute?

So here is my question, Question: A water sample contains 9.5% $\mathrm{MgCl_2}$ and 11.7% $\mathrm{NaCl}$ (by weight). Assuming 80% ionization of each salt. Boiling point of water will be ________....
Saharsh's user avatar
  • 812
-1 votes
1 answer
5k views

How to calculate the molar mass of a protein from its osmotic pressure?

I am unsure how to go about solving this question. I know how to get the osmotic pressure, but where do I go from there? I can't use the gas law since the protein is not a gas. $\pu{2.38 g}$ of a ...
Klik's user avatar
  • 720