How to Calculate the Moles of a Compound. How to Convert Micrograms to Micromoles. How Do I Calculate Molarity? How to Convert Moles to Molecules. How to Convert Atoms to Grams. What Are Representative Particles of Elements? How to Calculate Atomic Mass. How to Calculate Mmol. How to Convert Grams to Milligrams. How to Calculate the Number of Moles in a Solution. Density to Molarity Conversion. From the selection list, choose the unit that corresponds to the value you want to convert, in this case 'Millimole [mmol]'.
Finally choose the unit you want the value to be converted to, in this case 'Mole [mol]'. Then, when the result appears, there is still the possibility of rounding it to a specific number of decimal places, whenever it makes sense to do so.
With this calculator, it is possible to enter the value to be converted together with the original measurement unit; for example, ' Millimole'. In so doing, either the full name of the unit or its abbreviation can be usedas an example, either 'Millimole' or 'mmol'. Then, the calculator determines the category of the measurement unit of measure that is to be converted, in this case 'Amount of substance'. After that, it converts the entered value into all of the appropriate units known to it.
In the resulting list, you will be sure also to find the conversion you originally sought. For this alternative, the calculator also figures out immediately into which unit the original value is specifically to be converted. We can also use moles to measure other particles such as molecules or electrons, but we would need to specify which particles are in use in this case.
Molar concentration is also sometimes called molarity. We have to be careful not to confuse molarity with another related property, molality. Unlike molarity, molality is the ratio of the amount of substance of the solute to the mass of the solvent, and not to the mass of the entire solution.
In some cases, values for molarity and molality of a solution are very close. This is the case if our solvent is water, and if the amount of solute is small enough that its mass and volume are insignificant — but this is not always the case. Molar concentration can be affected by temperature, although this depends on the substances present in this solution. Temperature can cause some solvents to expand, and if the solute does not expand with the solvent, then the molar concentration decreases.
It is also possible for the solvent to evaporate while the amount of the solute remains the same, as the temperature increases. In this case, the concentration of the solution will increase. In some cases, the opposite happens. Sometimes raising or lowering the temperature changes the solubility. As a result, all or parts of the solvent stop being dissolved in the solution, and the concentration is decreased.
Molar concentration is measured in moles per unit of volume, for example in moles per liter or moles per cubic meter. The latter is the SI unit. It can also be measured in moles per another unit of volume. To find molar concentration we need to know the amount of substance and the total volume of the solution.
To determine the amount of the substance we could use the molecular formula for this substance and information about the mass of this substance that is present in the solution. In particular, to find how many moles of the solution we have, we can look up the atomic mass of each atom present in the molecule in the periodic table, and then divide the total mass of the substance by the total atomic weight of atoms in the molecule.
We have to make sure that before we add the atomic masses together, we multiply each of the atomic masses for a specific atom by the number of atoms of this type present in the molecule. The reverse is also possible. If we know the molar concentration of our solution and the formula of the solute, then we can determine the amount of solvent present in the solution, both in moles and in grams. For this, we will need to check the periodic table for the atomic weights, as described earlier.
Let us calculate the molarity of a solution that has 3 tablespoons of baking soda mixed with 20 liters of water.
We will work with atoms in this example, so let us find the atomic masses for sodium Na , hydrogen H , carbon C , and oxygen O. Now let us add these atomic masses. We will get The atomic masses in the periodic table are generally specified in atomic mass units. This is the case with our data as well. This atomic mass in atomic mass units corresponds to the mass of 1 mole of an element in grams. We were given 51 grams of soda. Let us find how many moles we have by dividing the total amount of 51 grams by the number of grams in one mole, or 84 grams.
We get about 0. This means that we diluted 0. Let us divide this amount of the baking soda by 20 liters to get the molar concentration: 0. We got a low concentration because we used such a small amount of soda and diluted it in a large volume of water. Let us try another example and find a molar concentration of 1 cube of sugar in one cup of tea. Table sugar is made up of sucrose.
For convenience, molar concentration is often used when working with chemical reactions. The branch of chemistry that deals with determining the quantities of initial substances and products of chemical reactions, stoichiometry , often deals with molar concentration. We can find molar concentration by using the chemical formula of the final component that becomes a solute, as we did for the baking soda, but we can also use chemical equations to find it.
We will need to know the formulas and the amounts for the substances reactants that are being used for our chemical reaction to create the solute as the final product. We will then have to balance the equation to find out the resulting product, and then use the periodic table, as described above, to find the needed information for calculating molar concentration.
In this case, we can also do the reverse as well, if we know the molar concentration. Let us look at a simple example. We will use baking soda again, and mix it with vinegar for an interesting chemical reaction. You can find these substances easily, you probably already have them in your pantry. The concentration can be smaller, depending on the manufacturer and the country of origin, because different concentrations are considered standard in different countries.
We do not have to worry about water in this reaction because water and baking soda do not react with each other. We can then mix sodium acetate with water and proceed with calculating the molar concentration, as we did in the earlier example for baking soda.
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