Molarity is a unit of concentrationmeasuring the number of moles of a solute per liter of solution. The strategy for solving molarity problems is fairly simple.
The key to calculating molarity is to remember the units of molarity M : moles per liter. Find the molarity by calculating the number of moles of the solute dissolved in liters of a solution. This example has neither the moles nor liters needed to find molarityso you must find the number of moles of the solute first.
Use this number to convert grams to moles. Now the liters of solution is needed. Keep in mind, this is the total volume of the solution, not the volume of solvent used to dissolve the solute.
This example is prepared with "enough water" to make mL of solution. Make certain to use the correct number of significant figures when reporting your answer.
How to Calculate Molarity of a Solution
One easy way to track the number of significant digits is to write all your numbers in scientific notation. Share Flipboard Email. By Todd Helmenstine. Todd Helmenstine is a science writer and illustrator who has taught physics and math at the college level. He holds bachelor's degrees in both physics and mathematics.
ppm to mg/liter conversion
Dilution Factor Calculator - ppb, ppm, ppt, pph. When a concentrated solution is diluted, the dilution factor may be expressed as the ratio of the concentration of stock solution to the concentration of the diluted solution.
The dilution factor may also be expressed as the ratio of the volume of the final diluted solution to the initial volume removed from the stock solution. See below for the dilution factor equations. For example, if a solution with a concentration of 1 ppm is diluted to yield a solution with a concentration of 1 ppb, the resulting dilution factor is For this particular dilution, it can also be said that the stock solution was diluted fold. It can also be said that the stock solution was diluted fold.
Therefore, a fold dilution is the same as a dilution factor of Thus, dilution by any factor X is equivalent to X -fold dilution. If you wish to convert these units to other volume units, please use our Unit Conversion Calculator. Additional dilution factor calculators are also available and are suited to more specialized applications see here. Each calculator cell shown below corresponds to a term in the formula presented above. Two main options are available for this calculator: the dilution factor may either be calculated or specified.
Dilution factor calculated : For this calculation, enter appropriate values in all cells except the dilution factor and the one you wish to calculate. Therefore, at least three cells must have values, and the dilution factor and the parameter you wish to calculate must be blank.By Peter J. Mikulecky, Chris Hren.
Percent to ppm Conversion
Two important ways to measure concentration are molarity and percent solution. Different solutes dissolve to different extents in different solvents in different conditions. To keep track of all these differences, chemists measure concentration. Qualitatively, a solution with a large amount of solute is said to be concentrated.
A solution with only a small amount of solute is said to be dilute. Quantitatively, we use numbers; hence, molarity and percent solution. To calculate molarity, you may have to use conversion factors to move between units. Units are the very first thing to check if you get a problem wrong when using molarity.
Make sure your units are correct! Note that this does not mean that there are 0. Percent solution is another common way to express concentration. The precise units of percent solution typically depend on the phase of each component. For solids dissolved in liquids, mass percent is usually used:. Sometimes, the term percent solution is used to describe concentration in terms of the final volume of solution instead of the final mass.
For example:. This is a mass-volume percent solution.
This is a volume-volume percent solution. Clearly, paying attention to units is important when working with concentration. Be sure to use proper units. First, calculate the molarity. Before you can use the molarity formula, though, you must convert grams of H 3 PO 4 to moles:. Note that the convention in molarity is to divide moles by liters, but the convention in mass percent is to divide grams by milliliters.
If you prefer to think only in terms of liters not millilitersthen simply consider mass percent as kilograms divided by liters.
Christopher Hren is a high school chemistry teacher and former track and football coach. Peter J. About the Book Author Christopher Hren is a high school chemistry teacher and former track and football coach.Molarity and parts per million ppm are two units of measurement used to describe the concentration of a chemical solution. One mole is equivalent to the molecular or atomic mass of the solute. Parts per million, of course, refers to the number of molecules of solute per million parts of a solution.
Since both of these units of measurement are commonly referred to in chemistry, it's helpful to understand how to convert from one to the other. This example problem demonstrates how to convert molarity to parts per million.Dilution Problems - Chemistry Tutorial
To do this, convert moles to mg. You can perform the unit conversion the other way, too.
Use the atomic masses from the periodic table to find the molar mass of the solute. The mass of sodium doesn't come into play since we're only looking at chloride ions for this problem. So, you now have the relation:. You either move the decimal point over one space to the left or multiply this value times 0. Share Flipboard Email. Anne Marie Helmenstine, Ph. Chemistry Expert. Helmenstine holds a Ph. She has taught science courses at the high school, college, and graduate levels.
Facebook Facebook Twitter Twitter. Updated January 31, For example, let's find the ppm concentration of chloride ions in a 0.
Units of Concentration: Osmolarity and Osmolality in Chemistry.It will help you convert between both of these ratios for the solution of any substance in water. It also allows you to find the molar concentration of the solution. Imagine that you add 10 grams of a substance to a liter of water. If the substance is dense, like oil, it will have a smaller volume - and consequently, the solution will have a smaller PPM ratio. It means that every cubic meter of water weighs kg.
Let's recalculate the units:. That means that every liter of water contains exactly a million milligrams of water. Remember that this equality is valid only for very specific conditions - pure water at a standard pressure and temperature.
To find the molarity, you need to know an additional parameter - the molar mass of your solute substance dissolved in water. It is expressed in grams per mole.
Use the following formula:.
Get the HTML code. Omni Calculator logo Embed Share via. Parts per million. Solute density. Milligrams per liter. Solute molar mass. Molar concentration. Check out 33 similar conversion calculators.
Weight converter. Temperature conversion. PPMor parts per million, is the number of parts of a substance in a million parts of the solution or mixture.In the same way you might say you have a 7 percent solution, you might say that you have a 36 PPM solution.
There are a couple of situations where a PPM calculation is very easy to do. One of these is the conversion from a percentage value to a PPM value because 1 PPM is just 10, times bigger than one percent. To perform the conversion, then, simply multiply the value in percent by 10, or 10 4. For example, if you have a 0. Another easy example is a rare case when you can easily mix masses and volumes and convert to PPM. In general, though, you can always calculate PPM using one approach and a simple formula.
Then you can use the following formula to find the concentration:. Just remember that you need to keep the same units, and the process is simple.
Lee Johnson is a freelance writer and science enthusiast, with a passion for distilling complex concepts into simple, digestible language. He's written about science for several websites including eHow UK and WiseGeek, mainly covering physics and astronomy.
He was also a science blogger for Elements Behavioral Health's blog network for five years. He studied physics at the Open University and graduated in About the Author. Copyright Leaf Group Ltd.The unit ppm is used in several branches in different ways. The use of ppm therefore has to be specified in the input fields below, in the way it should convert the value with the proper unit. For more theory about the use of ppm, please see the documentation below. In the input field of Molecular Weight you could either choose from the drop-down list, or you could fill in the value of the molecular weight of the gas.
If the molecular weight is unknown to you, please try our Molecular Weight Calculator. The significance is automatically determined. Use extra zero's to expand the significance. In air pollution literature ppm applied to a gas, always means parts per million by volume or by mole. These are identical for an ideal gas, and practically identical for most gases of air pollution interest at 1 atm. Another way of expressing this value is ppmv. Today's more and more there is an interest to express gas concentrations in metric units, i.
Additionally, because of difference in molecular weight, comparisons of concentrations of different gases are difficult. The density of gas can be calculated by the Law of Avogadro's, which says: equal volumes of gases, at the same temperature and pressure, contain the same number of molecules.
This law implies that 1 mole of gas at STP a volume of For converting ppm by mole, the same equation can be used. This can be made clear by the following notation:. By checking the dimensions of the most right part of the equation, there will be found a dimensionless value, like the concentration in ppm is. To calculate the concentration in metric dimensions, with other temperature and pressure conditions the Ideal Gas Law comes in handy. The volume V divided by the number of molecules n represents the molar volume V n of the gas with a temperature T and pressure P.
With this equation it comes clear that the percentage notation by ppm is much more useful, because the independency of the temperature and pressure.
Parts per Million by Weight in Water The concentration in ppm of gas in water is meanly meant by weight. To express this concentration with metric units the density of water is needed.
The density of pure water has to be by definition Till then this was mean definition for the kilogram. Today's the kilo is defined as being equal to the mass of the international prototype of the kilogram . Even the concerning concentration of gas dissolved in the water is affecting the density of the solution. By nature there's a chance that water contains a certain concentration of Deuterium which influences the density of the water.
This concentration is also called the isotopic composition . Accurate calculations on these conversions are only possible when the density of the water is measured. In practice the density of water is therefore set to 1.