Arrange the following diatomic molecules in order of weakest to strongest bond: HF, HCl, HBr, and HI.
Remember this.
Bond strength is a function of electronegativity as one goes from the left to the right in the periodic table.
So CO2, NH3, HF is stronger from left to right.
Bond strength decreases as we go DOWN the table because of size. So HF is stronger than HCl > HBr etc.
The strength of a bond is determined by the electronegativity difference between the two atoms in the molecule. The larger the electronegativity difference, the stronger the bond.
In this case, we can compare the electronegativity values of the atoms in each diatomic molecule:
HF: H has an electronegativity of 2.2, and F has an electronegativity of 3.98. The electronegativity difference is 1.78.
HCl: H has an electronegativity of 2.2, and Cl has an electronegativity of 3.16. The electronegativity difference is 0.96.
HBr: H has an electronegativity of 2.2, and Br has an electronegativity of 2.96. The electronegativity difference is 0.76.
HI: H has an electronegativity of 2.2, and I has an electronegativity of 2.66. The electronegativity difference is 0.46.
Based on the electronegativity differences, we can arrange the molecules from weakest to strongest bond:
HI < HBr < HCl < HF.
To determine the order of weakest to strongest bond for the diatomic molecules HF, HCl, HBr, and HI, we need to consider the factors that influence the strength of the bond.
The bond strength in a diatomic molecule is primarily influenced by the electronegativity difference between the two atoms. Electronegativity is a measure of an atom's ability to attract electrons towards itself. The greater the electronegativity difference, the stronger the bond.
Here's how you can determine the order of weakest to strongest bond:
1. Find the electronegativity values for the atoms involved in each diatomic molecule. You can use a periodic table or reference materials to obtain these values. For our purpose, we'll use the following values:
Hydrogen (H): 2.2
Fluorine (F): 3.98
Chlorine (Cl): 3.16
Bromine (Br): 2.96
Iodine (I): 2.66
2. Calculate the electronegativity difference between the atoms in each diatomic molecule by subtracting the electronegativity of the less electronegative atom from the more electronegative atom.
For HF: Electronegativity difference = 3.98 - 2.2 = 1.78
For HCl: Electronegativity difference = 3.16 - 2.2 = 0.96
For HBr: Electronegativity difference = 2.96 - 2.2 = 0.76
For HI: Electronegativity difference = 2.66 - 2.2 = 0.46
3. Arrange the diatomic molecules in order of increasing electronegativity difference (weakest to strongest bond).
From our calculations, the order will be: HI < HBr < HCl < HF
Therefore, the order of weakest to strongest bond for the diatomic molecules is: HI < HBr < HCl < HF.