given the following electronegativities Na=0.9, H=2.1, Cl=3.0 which of the following statements is true?
H2,Cl2, and HCl are polar covalent molecules
NaCl is a polar covalent compound and HCl is an ionic compound
HCl is a nonpolar covalent compound and Cl2 is a polar covalent molecule
Cl2 is a nonpolar covalent molecule and HCl is a polar covalent molecule
please explain why. I am having a hard time comprehending this stuff
thanks
Cl2 is nonpolar and HCl is polar because electronegative increases form left to right and decreases going down the periodic table.Also,Cl2 is diatomic and diatomics are nonpolar.
Subtract to obtain the delta EN. Delta EN of about 1.8 or so is about 50/50.
cfsfa
To determine the nature of a compound or molecule (polar covalent, nonpolar covalent, or ionic), we need to compare the electronegativities of the atoms involved in the bond.
Electronegativity is a measure of an atom's attraction for shared electrons in a covalent bond. The greater the difference in electronegativity between two atoms, the more polar the bond will be.
Now let's go through each statement and analyze the electronegativities:
Statement 1: H2, Cl2, and HCl are polar covalent molecules.
For H2: Both hydrogen atoms have the same electronegativity (2.1), so the bond is nonpolar.
For Cl2: Both chlorine atoms have the same electronegativity (3.0), so the bond is nonpolar.
For HCl: The electronegativity of hydrogen is 2.1, and chlorine is 3.0. The difference in electronegativity is significant enough to classify the bond as polar.
So, this statement is not true because H2 and Cl2 are nonpolar covalent molecules, but HCl is a polar covalent molecule.
Statement 2: NaCl is a polar covalent compound, and HCl is an ionic compound.
For NaCl: The electronegativity of sodium is 0.9, and chlorine is 3.0. The difference in electronegativity is large, suggesting an ionic bond.
For HCl: The electronegativity of hydrogen is 2.1, and chlorine is 3.0. The difference in electronegativity is significant enough to classify the bond as polar covalent, not ionic.
Hence, this statement is also not true because NaCl is an ionic compound, but HCl is a polar covalent compound.
Statement 3: HCl is a nonpolar covalent compound, and Cl2 is a polar covalent molecule.
We already discussed that HCl is a polar covalent compound due to the electronegativity difference between hydrogen and chlorine.
For Cl2: Both chlorine atoms have the same electronegativity (3.0), so the bond is nonpolar.
Therefore, this statement is not true either because HCl is a polar covalent compound, but Cl2 is a nonpolar covalent molecule.
Statement 4: Cl2 is a nonpolar covalent molecule, and HCl is a polar covalent molecule.
This is the correct statement.
So, the answer is Statement 4: Cl2 is a nonpolar covalent molecule, and HCl is a polar covalent molecule.