For which one of the following is the density maximum ?

Density is defined as mass per unit volume. Comparing the given substances at standard conditions (approximately 20-25°C), Chloroform (CHCl3) has the highest density at approximately 1.48-1.49 g/cm⊃3 [t3][t9]. In contrast, pure water has a maximum density of approximately 1.00 g/cm⊃3 at 4°C [c1][t4]. Benzene (C6H6) is less dense than water, with a density of about 0.87 g/cm⊃3 [t4][t9]. Ice, the solid form of water, is even less dense than liquid water (approximately 0.917 g/cm⊃3), which is why it floats [c2][c3]. Chloroform's high density is primarily due to the presence of three heavy chlorine atoms (atomic weight ~35.5 each) attached to a single carbon atom, significantly increasing its molecular weight (119.37 g/mol) relative to its molecular volume [t3][t9]. Therefore, among the options provided, Chloroform is the densest substance.

Sources

1. [1] https://pubchem.ncbi.nlm.nih.gov/compound/Chloroform
2. [2] Science ,Class VIII . NCERT(Revised ed 2025) > Chapter 9: The Amazing World of Solutes, Solvents, and Solutions > Conversion factor for density > p. 141
3. [3] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 12: Water (Oceans) > SALINITY OF OCEAN WATERS > p. 104
4. [4] Science , class X (NCERT 2025 ed.) > Chapter 9: Light – Reflection and Refraction > 9.3.2 The Refractive Index > p. 149