What is Concentration: Definition and 583 Discussions

In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture. Several types of mathematical description can be distinguished: mass concentration, molar concentration, number concentration, and volume concentration. A concentration can be any kind of chemical mixture, but most frequently solutes and solvents in solutions. The molar (amount) concentration has variants such as normal concentration and osmotic concentration.

View More On Wikipedia.org
Recent contents Top users
  1. M

    Calculate concentration of halfcell

    Hello Im completely stuck on this question and don't know where to begin or what to do.. and help or guidance is appreciated: A voltaic cell at 25oC consists of Mn/Mn2+ and Cd/Cd2+ half-cells with an initial cell potential of +0.768 V. The [Mn2+] concentration is 0.500 M. Use the Nernst...
  2. S

    Beer lambert equation and concentration

    Please help, A 15.23mg sample of cocaine was cemically digested to convert its nitorgen to ammonia and then diluted to 100.00cm3. A 10.00cm3 of this solution was placed in a 50.00cm3 volumetric flask and treated with 5.0cm3 of phenol solution and 2.0cm3 of sodium hypochlorite solution. The...
  3. A

    Help with percent concentration of hydrogen peroxide if diluted?

    :frown: I did an experiment on the effect of substrate concentration on the rate of a catalase. I was given 6% substrate concentration of hydrogen peroxide. We had to do 3 trials with different concentrations of the hydrogen peroxide but we had to dilute the peroxide ourselves in the second...
  4. D

    Concentration and pressure problem. Need help

    Ammonium carbamate (NH2COONH4) is found in the blood and urine of mammals. At a temperature of 442 K, Kc = 0.043 for the following equilibrium: NH2COONH4(s) <=> 2 NH3(g) + CO2(g). If 10.2 g of ammonium carbamate is introduced into a 0.500 L container, what is the total pressure inside the...
  5. Garth

    An anomalous concentration of QSOs around NGC 3079

    An anomalous concentration of QSOs around NGC 3079 by E.M. Burbidge, G. Burbidge, H.C. Arp and W.M. Napier - who else? Abstract: So allowing for the lensing pair there are 20 QSOs in the location, which represent around a one in a million chance. But are there not a million or so (indeed...
  6. S

    Concentration Graphs: Instantaneous time

    im having troubles with this the teacher wants us to find hte instantaneous rate of reaction at time 60 seconds , so i trace 60 s to the graph and make a point where it meets. Now i draw a tangent to this point. This is what gets me, how long should this tangent me, because i kow i have to get...
  7. A

    PH: product of concentration of H+ and OH-

    Why is the following true?: \left[H^+\right]\left[OH^-\right]=10^{-14} It seems like they would cancel out (equal 10-7 instead). Thanks for your help.
  8. C

    Relationship between molarity & concentration?

    Hello! In my chemistry lab we did an experiment where the purpose was to find the estimated concentration of sugar in unknown solutions. We used 10 mL of each solution, and I determined the mass of the solution of each unknown. From there I calculated the density (mass over volume). Using that I...
  9. O

    Figuring Out Patent Blue Solution Concentration

    Hello :blushing: I need help trying to figure this out: Patent blue V is a food coloring designed under the code E 131. Using a scales of blue tints, we hope to determine the molar concentration of patent blue in a solution used to color candy in a candy shop. We make a range of tints...
  10. K

    Solving Concentration Problem in Tank

    Hi I'm a newbie and i have a problem here that i cannot solve, or i don't know how to solve. Hope you experts can help me out! Here it is: A tank contains 10 kg of sodium hydroxide in 1000 litres of water. Water is continuosly added to the tank at a rate of 5 litres/min so that the mixture is...
  11. S

    Optimizing dNTP Concentrations for PCR Reactions

    Does the concentration of dNTP in the bottle's label specified the total concentration of the four nucleotides or only each of them? When it says in the protocol "each 200uM" does it mean that i have to add a concentration 4 fold (200uM * 4) of the bottle to get all the four different...
  12. N

    Concentration Citric Acid in Lemon Juice?

    Hey there ppl! I am doing an Acid/Base Titration to investigate whether the concentration of citric acid lemon juice, change over a period of 5 days. So i kindda need some help in this experiment, cause we are not allowed to ask our teacher any help! The main purpose of this experiment is that...
  13. M

    Is Your RNA Concentration Measurement Accurate? Tips for Better Results

    Do you have any good protocols for measuring the concentration of RNA? The ones i have they seem to be very confused. Thanks.
  14. G

    Gas Concentration: ppm by Volume vs mg/L

    a gas is x ppm by volume Liquids are mg/L but what about the gas?
  15. R

    Concentration of Point Defects

    A question for anyone that has the ability to answer: I understand the difference between Frenkel and Schottky defects, and I also know that in different crystal structures, which one is predominant is different. I was wondering, what dictates which defect is the dominant one? Thanks for...
  16. G

    H+ concentration gradient Photosynthesis

    FOr the light dependent reaction, In the textbook it says that the H+ concentration gradient across the thylakoid membrane is maintained by: 1) photolysis 2) transport of electrons from photosystem II along carriers 3) formation of NADPH. I can understand 1) and 3), but I have no idea...
  17. P

    Equilibrum Concentration Problem

    H2(g) + I2(g) = 2HI at a temperature T If 1.40 mol H2 and 3.50 mol I2 are placed in a 1.00 L vessel, what is the equilibrium concentration of I2 in the gaseous mixture? The equilibrium constant is K = 49.7 x 10 10 HINT You can use the...
  18. P

    Chemical Equilibrium, finding concentration

    H2(g) + I2(g) = 2HI(g) T = 731K K = 49.0 If at equilibrium 0.171 mol H2 and 1.571 mol I2 are present in a 1.04 L vessel, what is the concentration of HI in the gaseous mixture in moles/liter ? Ok I tried doing this question by setting up a mole ratio first...
  19. S

    Measuring protein concentration

    dear everybody! i am very confused about this area and hope that you can help me out of this. for example this protocol: 1. Add sufficient bovine gamma globulin to each of eight test tubes to give you a calibration curve. Suggested values are 0, 10, 20, 30, 60, 90, 120 and 150 µg/ul...
  20. D

    How Many Grams of Solute Are Needed for Specific Solution Concentrations?

    What mass of solute do you need to make 50 ml of a 20 g/L solution? \frac{20_g}{1000_{ml}}=\frac{x_{g}}{50_{ml}} 20 g/L = 1 g/50ml Answer: 1 g How many grams of solute are there in 300 g of .50% NaCl solution .50%=\frac{x_g}{300_{ml}} * 100 .005%=\frac{x_g}{300_{ml}} x=1.5 grams...
  21. D

    Simple Algebra (Concentration)

    Having a little trouble tackling this one. "What is the concentration of a 500 ml solution if, when diluted to a volume of 2 Liters, its new concentration becomes 20 g/L?" Here what I did, all in ml. \frac{x}{500+1500} \frac{x}{2000}=\frac{20}{1000} \frac{20*2000}{1000}=40=x...
  22. K

    Concentrate DNA in Learn How to Do It

    Is there by any way one can concentrate the DNA in a solution ?
  23. C

    Solution Concentration: Molarity

    Hello all I just need confirmation as to whether I am performing this problem correctly: How would you prepare 1.00 L of a 0.50 M solution of HCl from a 12M stock reagent? My solution: 1.00 L * (0.5 mol HCl/ L solution) = 0.5 mol HCl V * (12 mol HCl / L solution) = 0.5 mol HCl...
  24. matthyaouw

    How to improve your concentration

    This is a place full to the brim with academics, so maybe you can help me out here. What do you do when you have work to do, but you just can't seem to get on with it? My concentration is terrible at times, and today is no exception unfortunately... Surely some of you have had this problem before?
  25. D

    How Do You Calculate the New Concentration of IO3- After Dilution?

    How could i (mathematically) show what the concentration of IO3- in the following solution? 15mL of 0.20mol/L IO3- solution 5mL of water
  26. M

    Calculate the concentration of hydrogen peroxide

    can anone help me with these questions? a) How many moles of hydrogen peroxide react with each mole of permanganate in the titrationmoles of MnO4- per mole of H2O2 b) Calculate the concentration of hydrogen peroxide in the 10 mL aliquot, taken from the reaction if the titration with...
  27. M

    Concentration of water vapor present at equilibrium

    3 Fe (S) + 4 H2O (g) = Fe3O4 + 4 H2 (g) This equilibrium has a Kc of 4.6 @ 850 degree C. Determine the concentration of water vapor present at equilibrium if the reaction is initiated using 8.00 grams H2 and an excess of iron oxide, fe3O4, in a 16.0 liter container. This is what I...
  28. M

    Rate law seconds and concentration

    could you check this? AB(g) → A(g) + B(g) Rate = k[AB]^2 k = 0.2L/mol∙S How long will it take for [AB] to reach 1/3 (one third) of its initial concentration of 1.50M? What is [AB] after 10.0 seconds? 2nd order overall reaction so: part A 1/[A] - 1/[A]o = (k)(t) 1/0.5 -...
  29. D

    Solving Trimethylacetic Acid Concentration Questions

    Heya's Having some problems with the following question: Trimethylacetic acid C_4 H_{11} COOHis a weak monoprotic acid. When 0.0010 mol of Trimethylacetic acid was dissolved in 100mL of water, the concentration of trimethylacetic ion was found to be 3.0 \times 10^{ - 4} mol.L^{ - 1} a)...
  30. G

    Finding out the concentration of an acid or base

    Hello I really need help for working out the concentration of an acid / base. 1) How can we use a simple thermochemistry measurement and a density measurement, to find the concentration of an acid or alkali? (other than titration) 2) How do you devise an experiment to estimate the...
  31. B

    Calculate Mass of Paradichlorobenzene for .05 Molal Solution

    Calculate the mass of paradichlorobenzene (M=147.01g/mol) that should be added to 20.00 ml of cyclohexane (d = .779g/ml) to make a .05 molal solution. I did this problem but i don't know if i did it correctly. first i found the mass of cyclohexane by using m=dv. (.05moles solute/kg...
  32. G

    Enzyme concentration on the rate of hydrolysis of casein

    I am currently working on an investigation on the effects of varying enzyme concentration on the rate of hydrolysis of casein. I have looked on the internet to work out the maximum rate, but they all depnd on one variable - substrate concentration. I cannot find any mathematical expressions to...
  33. Q

    Magnetic Concentration: Exploring Halbach Arrays & Maxwell's Eqs

    Is the soft iron core the only known way of concentrating magnetism? I know that Halbach arrays create a sort of "monopole" by canceling the field on one side of the magnet but that, in my opinion, is not really concentration but rather asymmetrical field distortion. Afterall, the array doesn't...
Back
Top