Question

Advance Study Assignment: The Geometrical Structure of Molecules

You are asked by your instructor to construct a model of the NH2Cl molecule. Being of a conservative nature, you proceed as directed in the section on Experimental Procedure.

First you need to find the number of valence electrons in NH2Cl2. For counting purposes with Lewis structures, the number of valence electrons in an atom of a main group element is equal to the last digit in the group number of that element in the Periodic Table.

N is in Group ____________ H is in Group ____________ Cl is in Group ____________ In NH2Cl there is a total of ____________ valence electrons.

The model consists of balls and sticks. How many holes should be in the ball you select for the N atom? ____________ the H atoms? ____________ the Cl atom? ____________ The electrons in the molecule are paired, and each stick represents a valence electron pair. How many sticks do you need? ____________

Assemble a skeleton structure for the molecule, connecting the balls and sticks to make one unit. Use the rule that N atoms form three bonds, whereas Cl and H atoms usually form only one. Draw a sketch of the skeleton below:

How many sticks did you need to make the skeleton structure?____________ How many sticks are left over? ____________ If your model is to obey the octet rule, each ball must have four sticks in it (except for hydrogen atom balls, which need and can only have one). (Each atom in an octet rule species is sur- rounded by four pairs of electrons.) How many holes remain to be filled?____________ Fill them with the remaining sticks, which represent nonbonding electron pairs. Draw the complete Lewis structure for NH2Cl using lines for bonds and pairs of dots for nonbonding electrons.

Describe the geometry of the model, which is that of NH2Cl. ____________ Is the NH2Cl molecule polar? ____________ Why?

Would you expect NH2Cl to have any isomeric forms? ____________ Explain your reasoning.

Would NH2Cl have any resonance structures? ____________ If so, draw them below.

Answer 1

N is in Group ____5th________ H is in Group ____1st________ Cl is in Group _______7th_____ In NH2Cl there is a total of _____14_______ valence electrons.

The model consists of balls and sticks. How many holes should be in the ball you select for the N atom? _______3_____ the H atoms? ___1_________ the Cl atom? _____1_______ The electrons in the molecule are paired, and each stick represents a valence electron pair. How many sticks do you need? ____3________

Assemble a skeleton structure for the molecule, connecting the balls and sticks to make one unit. Use the rule that N atoms form three bonds, whereas Cl and H atoms usually form only one. Draw a sketch of the skeleton below:

How many sticks did you need to make the skeleton structure?___3_________ How many sticks are left over? ________1____ If your model is to obey the octet rule, each ball must have four sticks in it (except for hydrogen atom balls, which need and can only have one). (Each atom in an octet rule species is sur- rounded by four pairs of electrons.) How many holes remain to be filled?______0______ Fill them with the remaining sticks, which represent nonbonding electron pairs. Draw the complete Lewis structure for NH2Cl using lines for bonds and pairs of dots for nonbonding electrons.

Describe the geometry of the model, which is that of NH2Cl. ___pyramidal_________ Is the NH2Cl molecule polar? _____electro negativity difference b/w N and Cl atom makes it is polar_______ Why?

Would you expect NH2Cl to have any isomeric forms? __no_____because all atoms are in one plane_____ Explain your reasoning.

Would NH2Cl have any resonance structures? ___no_________ If so, draw them below.