# 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.

515 questions
Filter by
Sorted by
Tagged with
98 views

### How does % purity on household products work?

For example, toilet bowl cleaner is 9.5% HCl. Does this mean that for every 90.5 moles of H2O (or other stuff) there is 9.5 moles of HCl? Does it mean that for every 90.5 g of H2O there are 9.5 g of ...
334 views

### Stoichiometry : dilution questions [closed]

I need 500 ml of 0.2 mol/L H2SO4 for a tutration lab. What volume in mL of the 18 mol/L stock solution should you use? I think this is a dilution question asking me to use C1V1=C2V2. I am confused ...
655 views

### Calculation of equivalent weight

When a solid element is reacted with chlorine, a gaseous chloride of vapor density $68.75$ is formed. If this reaction is performed at constant temperature and pressure, the volume of the system ...
508 views

283 views

35 views

### pH at different concentrations

In making gummies with pectin, the pH is very important and needs to be at or below 3.4. USP indicates dissolving it in a 10% solution to test the pH, while some use a 50% solution. I'm told the ...
4k views

### How can you determine whether a solution is dilute or concentrated given its concentration?

How can you determine whether a solution is dilute or concentrated given its concentration? I don't whether this is a stupid question or not but I couldn't find any answer.
96 views

### Quantitative determination of chemical composition of a simple unknown mixture

Unknown mixture A [$\ce{H2SO4}$ and $\ce{CuSO4}$] Unknown mixture B [$\ce{H2SO4}$ and $\ce{HNO3}$] (ranged between $\pu{0.1 - 0.3 M}$ for the solution) (E.g. if you are using Unknown ...
534 views

### Calculating total volume mixing NaCl and water

I'm (as a non chemist) trying to calculate the the volume of a NaCl solution. The problem is that I know the volume of water prior to mixing in NaCl, but I want to know the volume of the solution ...
104 views

### How can I compare liquid concentration to solid concentration?

Total novice here! I'm trying to determine which is more sensitive between two drug tests, 1 that uses ng/ml and the other that uses pg/mg. Is there a way to standardize concentrations to compare ...
1k views

### How to calculate the concentration of the elements after dissolution of iron(III) chloride?

I was presented with the following problem: In the laboratory you dissolve $\pu{24.7 g}$ of iron(III) chloride in a volumetric flask in water to a total volume of $\pu{375 ml}$. What is ...
180 views

### Beer's Law: Are the graphs of concentration/time and absorbance/time supposed to look very similar?

For my lab, I'm trying to figure out if the reaction between NaOH and crystal violet is a zeroth, first, or second reaction. My slope is 5.714*10^4 and y-intercept 0.008016. In logger pro, after ...
140 views

976 views

### Determine reaction concentration at chemical equilibrium with multiple reactions

I have a problem understanding how to calculate the change/dependence of the concentrations at the chemical equilibrium using multiple reactions. The concentration of my reactants and products at ...
433 views

### Do I use the Nernst equation when the concentrations of electrolyte in both half cells are equal?

I'm doing a chemistry report, and for my experiment I investigated the amount of voltage produced by different half cells in a voltaic cell. However, I tested them under nonstandard conditions as ...
2k views

### What source of error in an acid-base titration could lead to a higher reading of the acid concentration?

Methanoic acid ($\ce{HCOOH}$) is found in stinging nettles. In an analysis of the concentration of methanoic acid in a solution extracted from nettles, the solution was titrated with a standard ...
457 views

### How can I calculate the concentration of nanoparticles in water solution? [closed]

I have synthesized gold-silver bimetallic nanoparticles in water media by following this article. How can I calculate the concentration of my nanoparticles solution?
743 views

### Is 70% ethanol hygroscopic?

I'm currently doing some DNA extractions and I realized that in some protocols, they are saying that ethanol is hygroscopic. In this source, they are saying: 85% ethanol made with nuclease free ...
35k views

### What is the relation between molarity and molality? [closed]

Is the following equation correct: $$m = \frac{1000 \times M}{M \times M_b - 1000 \times d},$$ where $M$ - molarity, $m$ - molality, $d$ -density of solution, $M_b$ - molar mass of solute?