- (1) Like atomic weight and molecular weight, equivalent weight is also a number, it does not have any unit.
- (2) The weights of the substances that take part in a chemical reaction and the substances formed from it are in the…
- (3) All substances have a fixed atomic mass or molecular weight. The equivalent weight of all substances is not fixed.
What is equivalent in chemistry?
Equivalent (chemistry) An equivalent (symbol: equiv) is the amount of a substance that reacts with (or is equivalent to) an arbitrary amount of another substance in a given chemical reaction. It is an archaic unit of measurement that was used in chemistry and the biological sciences in the era before researchers knew how to determine…
What is the mass of an equivalent?
The mass of an equivalent is called its equivalent weight. In a more formal definition, the equivalent is the amount of a substance needed to do one of the following: react with or supply one mole of hydrogen ions (H +) in an acid–base reaction. react with or supply one mole of electrons in a redox reaction.
What is equivalent (EQ)?
The equivalent (Eq or eq) is a reasonably common measurement unit used in chemistry and the biological sciences. It is a measure of a substance’s ability to combine with other substances.
What is an equivalence point in chemistry?
In chemistry, an equivalence point is a term that is used while performing titration. It applies to any acid-base or neutralization reaction technically.
How do you find equivalents in chemistry?
To calculate molar equivalents for each reagent, divide the moles of that reagent by the moles of the limiting reagent: Note that the molar equivalency of sodium benzoate is 1. This is because sodium benzoate is the limiting reagent. Any reagents used in excess will have a molar equivalency greater than one.
What is the formula of equivalence?
To find the equivalent of an acid, divide the acid’s molar mass by the number of protons. Here is a simple example using sulfuric acid: (1×2+32×1+16×4)/2 = 49 g/mol. Finding the equivalent of a salt is also simple: multiply the number of metal atoms by their oxidation state, then divide its molar mass by the result.
What is an equivalent in organic chemistry?
Illustrated Glossary of Organic Chemistry – One equivalent. One equivalent: In reaction stoichiometry, the amount of one substance that reacts with one mole of another substance.
What is the unit of equivalent in chemistry?
0:0810:17What is an equivalent? | Lab values and concentrations | Khan AcademyYouTubeStart of suggested clipEnd of suggested clipBut there are some things that i wanted to point out so it says the equivalent is formally definedMoreBut there are some things that i wanted to point out so it says the equivalent is formally defined as the amount of a substance which will either react or supply with one mole of hydrogen ions an acid
What equivalence means?
Definition of equivalence 1a : the state or property of being equivalent. b : the relation holding between two statements if they are either both true or both false so that to affirm one and to deny the other would result in a contradiction. 2 : a presentation of terms as equivalent.
What is an equivalence class example?
Examples of Equivalence Classes If X is the set of all integers, we can define the equivalence relation ~ by saying ‘a ~ b if and only if ( a – b ) is divisible by 9’. Then the equivalence class of 4 would include -32, -23, -14, -5, 4, 13, 22, and 31 (and a whole lot more).
What is equivalent of solute?
Normality is defined as the number of equivalents of solute dissolved per liter of solution (equivalents/L = N) (Equations 1, 3, and 4). A 1 N solution is one in which exactly 1 equivalent of solute is dissolved in a total solution volume of exactly 1 L.
What does 3 molar equivalents mean?
A molar equivalent is the ratio of the moles of one compound to the moles of another. Once you determine the moles (or mmols) of each compound you can determine the molar equivilants. Usually you are relating the moles of the limiting reagent to the moles of other starting materials or reagents used in the reaction.
What are equivalent atoms?
Two spatially equivalent atoms in a molecule can only be totally equivalent if they are of the same type and related to one another by a center of inversion. 2. A group of totally equivalent atoms in a molecule cannot contain more than two atoms.
What is the difference between equivalent and mole?
It is frequently used in the context of normality. The equivalent is formally defined as the amount of a substance (moles) which will react with 6.022 x 1023 electrons. (This is Avogadro’s Number, which is the number of particles in a mole).
How do you calculate mEq?
The equation to get mEq is therefore [(30 mg)(2)]/(58.44 mg/mmol) = 1.027 mEq. Since there are 400 mL = 0.4 L, the concentration in mEq/L is therefore 1.027/0.4 = 2.567 mEq/L.
What is equivalent number?
Equivalent numbers are numbers that have the same value. Each type of number, such as fractions, decimals, or square roots, can be equivalent to other numbers of their types, or to numbers of different types, as long as they have the same value.
What is the equivalence law?
Two logical statements are logically equivalent if they always produce the same truth value. Consequently, p≡q is same as saying p⇔q is a tautology.
How do you calculate logical equivalence?
To test for logical equivalence of 2 statements, construct a truth table that includes every variable to be evaluated, and then check to see if the resulting truth values of the 2 statements are equivalent.
What does equivalence mean in logic?
Logical equivalence is a type of relationship between two statements or sentences in propositional logic or Boolean algebra. The relation translates verbally into “if and only if” and is symbolized by a double-lined, double arrow pointing to the left and right ( ).
How do you write a logically equivalent statement?
Two expressions are logically equivalent provided that they have the same truth value for all possible combinations of truth values for all variables appearing in the two expressions. In this case, we write X≡Y and say that X and Y are logically equivalent.
What is equivalent in chemistry?
Equivalent (chemistry) The equivalent (Eq or eq) is a reasonably common measurement unit used in chemistry and the biological sciences. It is a measure of a substance’s ability to combine with other substances. It is frequently used in the context of normality . Additional recommended knowledge.
Why are equivalents important in chemical analysis?
Equivalents have advantage over moles in quantitative analysis of reactions. The best feature of using equivalents is that there is no need to study much about the nature of reaction, i.e. no need to analyse and balance chemical equations. Equivalents of reactants react in equal numbers to yield the equal equivalents of products.
What is the prefix for milliequivalents?
In practice, the amount of a substance in equivalents often has a very small magnitude, so it is frequently described in terms of milliequivalents (mEq or meq) — the prefix milli denoting that the measure is divided by 1000. Very often, the measure is used in terms of milliequivalents of solute per litre of solvent (mEq/L). This is especially common for measurement of compounds in biological fluids; for instance, the healthy level of potassium in the blood of a human is defined between 3.5 and 5.0 mEq/L.
How many electrons are in a gram of hydrogen?
(This is practically true, since a gram of hydrogen is very close to a mole of hydrogen, and free hydrogen has one spare electron; hence one gram of hydrogen is effectively equivalent to 6.022 x 10 23 electrons.)
What is the n number of equivalents?
The n number of equivalents is the part of this equation is the quantity of charge in an equation, and what charge is used is depends on the scenario.
What is the importance of chemistry?
Chemistry is a gateway science. It is essential for understanding Biology, Material Science, Geology, Metallurgy, Solid-State Physics, Astrophysics, and a host of sub-disciplines in each field.
How much heat energy is needed to raise the temperature of 1 gram of water to one degree Celsius?
We know 1 calorie of heat energy is required to raise the temperature of 1 gram of water to one degree Celsius. Now how much mass of the given substance is raised by 1 degree by one calorie of heat would be the water equivalent of that substance.
How many grams of HCl are in a gram?
eg: the equivalent mass of HCl is 36.5 amu. Therefore, 36.5 grams of HCl would mean 1 gram equivalent of HCl.
How much heat does aluminium need to be to raise the temperature of water?
i.e. the specific heat of aluminium is almost 1/5 of that of water. From this we can conclude that the amount of heat required to raise the temperature of 1 gram of water to one degree will almost be equal to the amount of heat required to raise the the temperature of 5 grams of aluminium to one degree,so the water equivalent of aluminium is almost 5.
How is the n factor determined?
The n factor is determined by the reaction stoichiometrically, but not by the acid/base itself. The n factor is equal to the number of mole of H⁺ produced/consumed by each mole the acid/base, or the number of moles of OH⁻ consumed/produced by each mole of the acid/base in an acid-base reaction.
Is equivalent weight a mass?
Equivalent weight is really not a weight, it is a mass. Mass is the amount of matter in something, while weight is the gravitational pull on a mass. Since we are only dealing with different chemical compounds on Earth, and we are dealing with chemistry, it is acceptable to interchange weight and mass. We will use the term equivalent weight (EW) for this lesson, and it has a general formula of
How to find the equivalent of an element?
The equivalent of an element can be defined as the amount of the element that reacts with or supplies 1 mole electron in a reaction, so if you try a bit you can conclude that 1 equiv of an element is equal to 1/n mole of element where n is the valency of the element. (NOTE:- the equivalent of a substance can be different for different reactions, eg. 1 equiv of F e = 1/2 mole F e if it under goes to an oxidation state F e X 2 + and it will be 1/3 mole if it undergoes to an oxidation state F e X 3 + ).
What is the equivalent of a substance?
An equivalent (symbol: officially equiv; unofficially but often Eq) is the amount of a substance that reacts with (or is equivalent to) an arbitrary amount of another substance in a given chemical reaction. The mass of an equivalent is called its equivalent weight.
How many moles does 1 eq of NaCl give?
Now if you think a bit harder you can get to the point that one equiv of a salt is equal to 1/n mole of salt where n is the total number of charge either on cationic part or on anionic part (eg. in NaCl, total cationic/anionic charge = +1 so, 1 eq of NaCl= 1 mole NaCl, now if you pay your attention, you can notice that 1 mole NaCl will give 1 mole Na+ and 1 mole Cl- which is in accordance to what we said earlier.)
What is reaction stoichiometry?
In reaction stoichiometry, it is the amount of one substance that reacts with one mole of another substance.
How many equivs does a substance react with?
1 eqiv of a substance reacts with exactly 1 equiv of another substances to produce 1 equiv of each product.
What is equivalent mass?
Equivalent mass is molar mass divided by the n factor which isn’t always dependent on the other reactant. As a rule of thumb “One equivalence of one reactant reacts completely with one equivalence of another.”. These concepts of equivalence are extremely important in acid-base titration to determine the neutralisation point.
Why is equivalent concept used in chemistry for knowing concentration?
Now lets get to the question ” Why is equivalent concept is used in chemistry for knowing concentration? “, well you might yourself have got the answer that it is because it is much simpler to apply as you do not need the Stoichiometry of the reaction going on, equivalent concept works fine without it.
What is an equivalence point?
Equivalence point. October 7, 2019. In chemistry, an equivalence point is a term that is used while performing titration. It applies to any acid-base or neutralization reaction technically.
What happens to the solution at the equivalence point?
At the equivalence point, the solution will change its color naturally without any addition of an indicator in some reactions. This may be observed in transition metals where the oxidation state consists of different colors.
What are some examples of equivalence points?
Examples of equivalence point: The reaction of a strong acid with a strong base: Let suppose hydrochloric acid HCl (a strong acid) is taken as an analyte and sodium hydroxide NaOH (strong base) is taken as a titrant.
How is equivalence determined in titrimetry?
Here the equivalence point is determined by measuring the rate of temperature change produced by a chemical reaction. This property differentiates it from calorimetric titrimetry. Because thermometric titrimetry is a relative technique, it is not necessary to perform the titration under isothermal conditions. This type of titration can be conducted in plastics or even in glass vessels. To prevent stray draughts, these vessels are usually enclosed by causing any noise that disturbs the endpoint. Because of the ability of this type of titration to be conducted under ambient conditions, they are appropriate for routine process and quality control in the industry. The temperature will either increase or decrease during the titration process, depending on whether the reaction taking place between the titrant and analyte is exothermic or endothermic. It titration when all analyte has been consumed by the reaction, rate of temperature changes i.e. an increase or decrease determines the equivalence point and inflection in the temperature curve can be observed. The equivalence point can be observed precisely by employing the second derivative of the temperature curve. The software which is used in a modern automated thermometric titration system consists of regular advanced digital algorithms so that the noise generating from highly sensitive temperature probes does not cause any interference with the appearance of a regular, uniform second derivative peak that describes the endpoint. This technique has the ability of very high precision and the coefficient of variance (CVs) of less than 0.1 are usual. The latest thermometric titration temperature probes have a thermistor that forms one arm of a Wheatstone bridge. the best thermometric titration system can resolve temperature to 10-5 K if coupled to high-resolution electronics. If the temperature changes while performing titration become as little as 0.001K a sharp equivalence point will be obtained. Where there is an enthalpy change, this technique can be applied necessarily to any chemical reaction in a fluid, though the reaction kinetics plays an important role in calculating the sharpness of the endpoint. This point of titrimetry has been substantially applied to acid-base, EDTA, REDOX and precipitation titration. Important examples of precipitation titration include:
What is the titration point?
In other words, while titrating, it is a point where the amount of added titrant is enough to neutralize the analyte solution completely. The number of moles of titrant i.e. standard solution is equal to the moles of a solution having an unknown concentration. It is also known as the stoichiometric point because it is a point where the moles of acid is equal to the moles of the base that are needed to neutralize the solution. Note that acid to base ratio doesn’t need to be 1:1. This acid-base ratio is explained by the balanced acid-base chemical equation. Indicators can be used for this purpose, for example, methyl orange or phenolphthalein.
How to determine the equivalence point of a titration?
The determination of the equivalence point is done by calculating the amount of heat that is produced or absorbed by using a device known as an isothermal titration calorimeter. This type is usually used in titrations that involve biochemical reactions i.e., as enzyme binding.
What is the stoichiometric point of acid?
It is also known as the stoichiometric point because it is a point where the moles of acid is equal to the moles of the base that are needed to neutralize the solution. Note that acid to base ratio doesn’t need to be 1:1. This acid-base ratio is explained by the balanced acid-base chemical equation.
What is the equivalence point in chemistry?
She has taught science courses at the high school, college, and graduate levels. The equivalence point is a chemistry term you’ll encounter when you do a titration. However, it technically applies to any acid-base or neutralization reaction. Here’s its definition and a look at methods used to identify it.
What are the methods of determining the equivalence point?
Methods of determining the equivalence point include color change, pH change, formation of a precipitate, change in conductivity, or temperature change. In a titration, the equivalence point is not the same as the endpoint.
How to determine the equivalence point of an isothermal titration?
Isothermal Calorimetry – The equivalence point may be determined by measuring the amount of heat that is produced or absorbed using a device called an isothermal titration calorimeter. This method is often used in titrations involving biochemical reactions, such as enzyme binding.
What is the mole of a titrant?
The moles of titrant (standard solution) equal the moles of the solution with unknown concentration. This is also known as the stoichiometric point because it is where the moles of acid are equal to the amount needed to neutralize the equivalent moles of base. Note this does not necessarily mean the acid to base ratio is 1:1.
When is ampometric titration used?
Amperometry is used when the excess titrant is able to be reduced. The method is useful, for example, when titrating a halide with Ag + because it isn’t affected by precipitate formation.
What is precipitation in chemistry?
Precipitation – If an insoluble precipitate forms as a result of the reaction, it can be used to determine the equivalence point. For example, the silver cation and chloride anion react to form silver chloride, which is insoluble in water. However, it can be difficult to determine precipitation because the particle size, color, …
Is the equivalence point the same as the endpoint?
The equivalence point is not the same as the endpoint of a titration. The endpoint refers to the point at which an indicator changes color. More often than not, the color change occurs after the equivalence point has already been reached. Using the endpoint to calculate equivalence naturally introduces error .
How many milli equivalents are in a substance?
There are 1000 milli-equivalents in 1 equivalent of a substance.
What is the gram equivalent of a substance?
A gram equivalent of a substance has the same quantity as its equivalent weight.
What is the number obtained by dividing the atomic mass of an element by its valency called?
The number obtained by dividing the atomic mass of an element by its valency is called the Equivalent Weight of that element.
How much oxygen is equivalent to aluminum?
The equivalent weight of oxygen is 8. 96 grams of oxygen combine with 108 grams of aluminum. So 8 grams of oxygen will combine with 9 grams of aluminum. So the equivalent weight of aluminum is 9.
How much hydrogen is equivalent to 8 grams of oxygen?
Since 4 grams of hydrogen react with 32 grams of oxygen, so 1 gram of hydrogen will react with 8 grams of oxygen. So the equivalent weight of oxygen is 8.
What is the equivalent weight of oxygen?
Therefore, in most of the reactions, the equivalent weight of oxygen is 16/2 = 8. In most reactions of chlorine has 1 valency. Therefore, in most of the reactions, the equivalent weight of chlorine is 35.5/1 = 35.5.
What is volumetric analysis?
In volumetric analysis, a solution of a known concentration or strength is treated with a solution of unknown strength. After the reaction is completed, the volume of both the solutions is determined and by calculation the strength of the solution having known strength is determined.
What is the equivalent of a substance?
The equivalent of a substance, also known as the equivalent quantity of a substance, refers to the quantity of a substance that interacts with one mole of hydrogen ions (in an acid–base reaction) or electrons (in a redox reaction).
How to find the equivalent mass of a substance?
The formula for determining a substance’s equivalent mass depends on the class of the compound in question. It is easy to find the equivalent mass for oxides, for example: divide the molar mass of the compound by the valence of the non-oxygen element multiplied by its number of atoms. Let’s look at the equivalent mass for gold (III) oxide, with the formula Au₂O₃.
How to find the equivalent of an acid?
To find the equivalent of an acid, divide the acid’s molar mass by the number of pro tons. Here is a simple example using sulfuric acid: Finding the equivalent of a salt is also simple: multiply the number of metal atoms by their oxidation state, then divide its molar mass by the result.
How to calculate the equivalent mass of a base?
To calculate the equivalent mass of a base, simply divide the molar mass of the base by the number of hydroxyl groups. Take, for example, calcium hydroxide Ca (OH)₂. A few simple calculations yield an equivalent of 37g/mol.