Markovnikov's rule calculator

The world of organic chemistry is rich with fascinating rules that dictate how molecules interact with each other. Among these, Markovnikov's rule stands out, a principle that plays a key role in predicting the outcomes of certain chemical reactions. To make this rule's application easier for you, we present our user-friendly Markovnikov's Rule Calculator!

• What is Markovnikov's Rule?
• How to Use the Markovnikov's Rule Calculator?
• Example Application of the Calculator
• An Exception to the Rule

What is Markovnikov's Rule?

Named after Russian chemist Vladimir Markovnikov, this rule predicts the product of an addition reaction between an alkene and a hydrogen halide. Markovnikov's rule states that in such a reaction, the hydrogen (H) atom bonds to the carbon with the greatest number of hydrogen atoms already attached, while the halide (X) attaches to the other carbon.

This happens because the most stable intermediates, called carbocations, are formed. The stability of these carbocations increases with the number of alkyl groups attached to the carbon. Hence, Markovnikov's rule ensures that reactions proceed along the path of greatest stability.

In terms of a formula, consider a simple alkene like ethene (C2H4) reacting with HX:

H2C=CH2 + HX → H3C-CH2X

The hydrogen from HX attaches to the carbon with more hydrogens (H3C-), and the halide attaches to the carbon with fewer hydrogens (CH2X).

How to Use the Markovnikov's Rule Calculator?

Our interactive Markovnikov's Rule Calculator allows you to apply this rule seamlessly. Here's how to use it:

• Number of Alkyl Substituents on each Carbon of Alkene: Simply input the number of alkyl substituents on each carbon of your alkene.
• Hydrogen Halide: Select the hydrogen halide you're using from the dropdown menu.
• The calculator will automatically find the resulting molecule following Markovnikov's rule.

Example Application of the Calculator

Suppose we have propene (CH3CH=CH2), and we're adding HBr. The carbon with more alkyl substituents (CH3 group in this case) is where the bromine will add. Input '1' for the first carbon (as it has one alkyl substituent) and '0' for the second carbon in the calculator, and select HBr as your HX. The calculator will make the calculations for you, you'll see the result: CH3CHBrCH3, the bromine has added to the carbon with the most alkyl substituents!

An Exception to the Rule

There are always exceptions in organic chemistry. Under peroxide conditions, the reaction follows the Anti-Markovnikov rule. Here, the halogen will attach to the carbon with more hydrogen atoms. Our calculator also accounts for this exception - simply select HOOH in the dropdown to simulate peroxide conditions.

Remember, our Markovnikov's Rule Calculator is a learning tool that should be used alongside real-world applications of organic chemistry, which should always consider all factors influencing reactions and be performed in a controlled laboratory environment.