Polarity Water and Carbon Tetrachloride

Summary

This video explains the relationship between molecular shape and polarity, using two examples: carbon tetrachloride and water. Carbon tetrachloride is a symmetrical, nonpolar molecule with a tetrahedral shape, which shows no interaction with a charged rod. In contrast, water has an asymmetrical, bent shape and is polar. The video demonstrates that the polarity of water causes it to be attracted to the charged rod, highlighting the influence of molecular structure on polarity and physical behavior.

Takeaways

• 😀 Carbon tetrachloride has a symmetrical tetrahedral shape with chlorine atoms attached to a central carbon.
• 😀 The symmetry of carbon tetrachloride makes it a nonpolar molecule.
• 😀 The polarity of carbon tetrachloride is tested by using a charged Ebonite rod, which has no effect on its stream.
• 😀 Water has a bent shape, making it asymmetrical.
• 😀 The bent shape of water leads to its polar nature, unlike carbon tetrachloride.
• 😀 A charged rod attracts water due to its polarity, demonstrating the interaction between charged particles and polar molecules.
• 😀 The test with the Ebonite rod and water shows that polarity affects molecular behavior in electric fields.
• 😀 Symmetry in molecules plays a key role in determining whether they are polar or nonpolar.
• 😀 Carbon tetrachloride’s lack of polarity prevents any bending when exposed to a charged object.
• 😀 The demonstration highlights how polarity influences molecular interaction with external charges, especially in liquids like water.

Q & A

What is the shape of a carbon tetrachloride molecule?

The shape of a carbon tetrachloride molecule is tetrahedral, meaning it has four chlorine atoms symmetrically arranged around a central carbon atom.

Why is carbon tetrachloride considered a nonpolar molecule?

Carbon tetrachloride is considered nonpolar because of its symmetrical tetrahedral shape, which means the dipoles of the chlorine atoms cancel each other out.

What does the static charge on the Ebonite rod do in the experiment?

The static charge on the Ebonite rod is used to test whether the molecule is polar by seeing if it causes the stream of the molecule to bend.

Why does the stream of carbon tetrachloride not bend when exposed to the charged Ebonite rod?

The stream of carbon tetrachloride does not bend because it is a nonpolar molecule, and the static charge has no effect on it.

What is the shape of a water molecule?

A water molecule has a bent shape, with the oxygen atom at the center and two hydrogen atoms attached at an angle.

How does the symmetry of water contribute to its polarity?

The bent shape of water creates an asymmetry in the distribution of charge, leading to a polar molecule with partial positive charges on the hydrogen atoms and a partial negative charge on the oxygen atom.

Why does water respond to the charged Ebonite rod?

Water responds to the charged Ebonite rod because it is a polar molecule, and the static charge on the rod induces an attraction between the charges in the water molecule.

What is the key difference between the behavior of carbon tetrachloride and water in this experiment?

The key difference is that carbon tetrachloride, being nonpolar, shows no response to the charged rod, while water, being polar, is attracted to the rod.

What does the experiment demonstrate about the relationship between molecular shape and polarity?

The experiment demonstrates that the molecular shape plays a crucial role in determining whether a molecule is polar or nonpolar. Symmetrical molecules like carbon tetrachloride tend to be nonpolar, while asymmetrical molecules like water tend to be polar.

What type of charge does the Ebonite rod carry in this experiment?

The Ebonite rod carries a static charge, which is generated by rubbing it with the rabbit's fur.