Isomers refer to compounds that have the same molecular formula but are structurally different. When isomers only differ in the spatial arrangement of their atoms, they constitute spatial isomers, or stereoisomers, a group that also includes the optical isomers.

Molecules with the same molecular formula can be different because their atoms are connected in different orders. They have the same molecular formula but different structural formulas. We call them isomers. For example, there are two isomers with the molecular formula C₂H₆O.

Isomers are two or more compounds that have the same molecular formula, but have a different arrangement of atoms in a molecule.

Compounds that have the same molecular formula but different chemical structures are called isomers. Depending on what types of differences there are between the structures, it is possible to classify isomers into various sub-types. If you “click” on the named boxes there is a link to a definition and an example.

Compounds that have the same molecular formula but different chemical structures are called isomers. Remember isomerism is a property between a pair (or more) of molecules, i.e. a molecule is an isomer of another molecule.

As is true for all constitutional isomers, each different compound has a different IUPAC name. Furthermore, the molecular formula provides information about some of the structural features that must be present in the isomers.

Isomers are different compounds that have the same molecular formula but the atoms are attached in different ways. There are two classes of isomers (Figure 4.4): (1) constitutional isomers and (2) stereoisomers.

The molecular formula of a compound may be the empirical formula, or it may be a multiple of the empirical formula. Within each group, the compounds have the same empirical formula and percent composition but different molecular formulas. That they are different compounds is shown by their different boiling points.

The equation for percent composition is (mass of element/molecular mass) x 100. Find the molar mass of all the elements in the compound in grams per mole.

Divide the molar mass of the compound by the empirical formula mass. The result should be a whole number or very close to a whole number. Multiply all the subscripts in the empirical formula by the whole number found in step 2. The result is the molecular formula.

Concentration formula: To find the molar concentration of a solution, simply divide the total moles of solute by the total volume of the solution in liters.

Divide the mass of the solute by the total volume of the solution. Write out the equation C = m/V, where m is the mass of the solute and V is the total volume of the solution. Plug in the values you found for the mass and volume, and divide them to find the concentration of your solution.

Divide the number of moles present by the total volume of the mixture. The resulting value will be the molar concentration. The resulting equation for our example would be (2 moles / 0.5 L = 4 M).

Use the titration formula. If the titrant and analyte have a 1:1 mole ratio, the formula is molarity (M) of the acid x volume (V) of the acid = molarity (M) of the base x volume (V) of the base. (Molarity is the concentration of a solution expressed as the number of moles of solute per litre of solution.)

Step 1: Calculate the amount of sodium hydroxide in moles

1. Amount of solute in mol = concentration in mol/dm 3 × volume in dm 3
2. Amount of sodium hydroxide = 0.100 × 0.0250.
3. = 0.00250 mol.
4. The balanced equation is: NaOH(aq) + HCl(aq) → NaCl(aq) + H 2O(l)
5. So the mole ratio NaOH:HCl is 1:1.

Explanation: The given data is as follows. Therefore, calculate molarity of the solution as follows. Thus, we can conclude that the concentration (in molarity) of NaOH solution is 0.091 M.

48 % to 50 %

39.997 g/mol

Oxalic acid is suitable for use as a primary standard and can then be used to standardise other solutions.

Oxalic acid solution is a primary standard because it is highly pure, stable and does not change its concentration with environmental factors.

NaOH solution of known strength can not be prepared by weighing as it combines with CO2 and moisture to give Na2CO3, whereas a primary standard is a reagent that is very pure, representative of the number of moles the substance contains, and easily weighed.

A primary standard is a reference chemical used to measure an unknown concentration of another known chemical. It can be used directly when performing titrations or used to calibrate standard solutions.

A primary standard in metrology is a standard that is sufficiently accurate such that it is not calibrated by or subordinate to other standards. Primary standards are defined via other quantities like length, mass and time. Primary standards are used to calibrate other standards referred to as working standards.

A primary standard is a soluble solid compound that is very pure, with a consistent formula that does not change on exposure to the atmosphere, and has a relatively high molar mass. A secondary standard is a solution of known concentration derived from a primary standard.

Only those acids or bases areconsidered primary standard which are stable and hence their strength do not change with time. Strength ofNa2CO3 also do not change hence it isconsidered as a primary standard. Na2CO3 is used as primary standardbecause it’s solution’s molarity remains constant for a very long period.

Na2CO3 is used as primary standard because it’s solution’s molarity remains constant for a very long period. Originally Answered: Why is na2co3 used as a primary standard? Only those acids or bases are considered primary standard which are stable and hence their strength do not change with time.