# Question: What is shelf life t90?

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Shelf life is defined as the time necessary for the drug to decay to 90% of its original concentration. t90= 2,303.

## What is t90 in chemical kinetics?

Different chemical kinetic parameters of the markers were evaluated by Arrhenius equation to predict shelf life (t90) at different storage conditions and at room temperature. The predicted shelf life (t90) of the markers at room temperature was found to be 16 months approximately.

## What is shelf life stability?

Shelf life is typically expressed in units of months, i.e. 24 months, 36 months, to a maximum of 60 months. This is why “shelf life testing” is also referred to as “stability testing”. The amount of time a product can stay stable under certain environmental conditions, equates to its shelf life.

## How to define shelf life?

Shelf life is defined as the length of time a product may be stored without becoming unsuitable for use or consumption. Shelf life depends on the degradation mechanism of the specific product. Freezing foods prevents spoilage and preserves taste, but some frozen foods have a specific and defined shelf life.

## What is the difference between stability and shelf life?

The number of days that the product remains stable at the recommended storage conditions is referred to as the shelf life. The experimental protocols commonly used for data collection that serve as the basis for estimation of shelf life are called stability tests.

## What is the unit of k0 )?

The units of the rate constant, k, depend on the overall reaction order. The units of k for a zero-order reaction are M/s, the units of k for a first-order reaction are 1/s, and the units of k for a second-order reaction are 1/(M·s). Created by Yuki Jung.

## What is difference between order and Molecularity?

We define order of reaction as the number of molecules of the reactant whose concentration changes during the chemical change. Molecularity is the number of ions or molecules that take part in the rate-determining step. To determine order we should sum up the exponents from the rate law of the equation.

## What is the unit of k for second order reaction?

The units of the rate constant, k, depend on the overall reaction order. The units of k for a zero-order reaction are M/s, the units of k for a first-order reaction are 1/s, and the units of k for a second-order reaction are 1/(M·s).

## What is rate constant k?

The specific rate constant (k) is the proportionality constant relating the rate of the reaction to the concentrations of reactants. A large value of the rate constant means that the reaction is relatively fast, while a small value of the rate constant means that the reaction is relatively slow.

## Can molecularity be negative?

The value of molecularity cannot be zero, negative, fractional, infinite, and imaginary. So, it can only be positive integer. The value of molecularity cannot be greater than 3 as more than three molecules may not mutually collide or come closer during the course of the chemical reaction.

## Is shelf life and expiration date the same?

The Facts. FACT: Shelf Life does NOT mean expiration date. FACT: A standards expiration date and shelf life are two entirely different entities. Chemical stability is only one of many factors involved in defining expiration date and shelf life.