Understanding the Index of Hydrogen Deficiency (IHD)

What does the Index of Hydrogen Deficiency (IHD) measure in a compound?

• The number of carbon atoms

• The molecular weight

• The degree of unsaturation

• The number of hydrogen atoms

How many degrees of unsaturation does a benzene ring contribute?

• One degree

• Two degrees

• Three degrees

• Four degrees

What is the first step in the formula-based method for calculating IHD?

• Add the number of nitrogens

• Multiply the number of carbons by two

• Subtract the number of hydrogens

• Divide by two

In the alternative method, what is done with the oxygens in the compound?

• They are counted as double bonds

• They are removed

• They are converted to hydrogens

• They are added to the formula

When using the alternative method, what happens to halogens in the compound?

• They are counted as rings

• They are converted to hydrogens

• They are ignored

• They are added to the formula

How many rings are present in guanine according to the structure-based IHD calculation?

• One ring

• Two rings

• Three rings

• Four rings

What is the IHD of guanine when calculated using the formula-based method?

• Four

• Seven

• Six

• Five

How many rings does cholesterol have according to the structure-based IHD calculation?

• Four rings

• Three rings

• Two rings

• Five rings

What is the IHD of cholesterol when calculated using the alternative method?

• Five

• Six

• Four

• Three

Which method might be easier for those who struggle with memorizing formulas?

• None of the above

• Alternative method

• Formula-based method

• Structure-based method