How do you calculate hydroxyl value?

The analytical method used to determine hydroxyl value traditionally involves acetylation of the free hydroxyl groups of the substance with acetic anhydride in pyridine solvent.

What is oil hydroxyl value?

The hydroxyl number, defined as the number of. milligrams of potassium hydroxide equivalent to. the hydroxyl content of 1 gram of fat, oil, or wax, may be determined with economies of sample, reagents, and time if the reaction is carried out.

How do you calculate molecular weight from hydroxyl?

*The molecular weight of KOH is 56.1. Since hydroxyl number (OH) is expressed in milliweights per unit weight, we must multiply 56.1 by 1000 to convert to OH, and the factor 56,100 appears in the calculations. OH is a dimensionless unit; it can be expressed in any weight system without altering its numerical value.

How do you calculate hydroxyl equivalent weight?

Equivalent Weight For an isocyanate, the reactive group is -N=C=O. (NCO. Its concerntration is measured by weight percent NCO).

What is hydroxyl value of polyol?

The hydroxyl number (OH#) is a measure of the concentration of the hydroxyl groups on the polyol. The number of reactive hydroxyl groups (OH) on the polyol directly impacts the quantity of urethane linkages, which greatly influences the physical properties of the final polyurethane product.

What is the significance of acid value?

The acid value (AV) in edible oils, defined as the amount of potassium hydroxide (KOH, in milligrams) necessary to neutralize the free fatty acids contained in 1 g of oil,1,2 is one of the important parameters related to the oil quality. A high AV indicates the deterioration of oil, which affects its nutritive value.

What does the saponification value tell you?

It is a measure of the average molecular weight (or chain length) of all the fatty acids present in the sample as triglycerides. The higher the saponification value, the lower the fatty acids average length, the lighter the mean molecular weight of triglycerides and vice-versa.

How do you calculate pH value?

To calculate the pH of an aqueous solution you need to know the concentration of the hydronium ion in moles per liter (molarity). The pH is then calculated using the expression: pH = – log [H3O+].

What is isocyanate index?

A term widely used in polyurethane foam technology, the isocyanate index is the excess of isocyanate over the theoretical amount for (1:1) reaction with all active H expressed in percentage terms (i.e. 1:1 = 100). Thus, Isocyanate index = 100 x (Actual amount of NCO used) / (Theoretical amount of NCO required)

What is an example of hydroxyl?

When hydroxyl groups are the primary functional group bonded to carbon backbones, the resulting molecules are alcohols. Methanol, isopropyl alcohol, and propanol are additional examples of alcohols containing the hydroxyl group. Carbohydrate molecules, or sugars, have hydroxyl groups, too.

What is the function of hydroxyl?

The addition of a hydroxyl group converts many organic compounds into alcohols, enhancing their solubility in water. Similar to carboxyl functionalized surfaces, the presence of hydroxyl groups has shown to support chondrogenic differentiation of hMSCs.

Which is the correct definition of the hydroxyl value?

Jump to navigation Jump to search. In analytical chemistry, the hydroxyl value is defined as the number of milligrams of potassium hydroxide required to neutralize the acetic acid taken up on acetylation of one gram of a chemical substance that contains free hydroxyl groups.

How is the hydroxyl value of potassium hydroxide calculated?

Hydroxyl value is a measure of the content of free hydroxyl groups in a chemical substance, usually expressed in units of the mass of potassium hydroxide (KOH) in milligrams equivalent to the hydroxyl content of one gram of the chemical substance.

What is the valence of the hydroxyl group?

Hydroxyl Group Definition: The hydroxyl group is a functional group consisting of a hydrogen atom covalently bonded to an oxygen atom. The hydroxyl group is denoted by -OH in chemical structures and has a valence charge of -1.

What is the medical definition of hydroxyl OH?

Medical Definition of hydroxyl. 1: the chemical group or ion OH that consists of one atom of hydrogen and one of oxygen and is neutral or positively charged.