Cyclic diether (1,3-dioxolane) and primary alcohols (pentanol, hexanol, heptanol, octanol, nonanol and decanol) were purchased from CDH Ltd., New Delhi, India. All the chemicals were stored in dark bottles over freshly activated molecular sieve to minimize adsorption of moisture. All chemicals were purified by standard methods like distillation and fractional distillation under reduce pressure, and only the middle fractions were collected. Before use, the chemicals were stored over 0.4 nm molecular sieves for about 48 h to remove water and gas. It sounds like you’re ensuring the reliability of your experimental data by comparing the density, viscosity, and ultrasonic velocity of the studied chemicals with different citations [13] - [22] . This verification process is crucial for validating the liquid and liquid mixtures.

Binary liquid mixtures are prepared by mixing appropriate volumes of the liquid components in the specially designed glass bottles with air tight Teflon coated caps and mass measurements performed on a analytical single pan balance (Model K-15 Deluxe, K Roy Instruments Pvt. Ltd.) with an accuracy of ± 0.00001 × 10⁻³ kg. The possible error in the mole fraction was estimated to be less than 1 × 10⁻⁴. Five samples were prepared for one system, and their density, viscosity and sound velocity were measured on the same day ( Table 1 ).

Density: The density was determined at the experimental temperature using a 25 mL capacity specific gravity bottle immersed in the thermostatic bath. The volume of the bottle at the experimental temperature viz 298.15K was ascertained using distilled water.

Sound velocity: Sound velocity determined by the multi-frequency interferometer at 3 MHz and 298.15 K, A fixed frequency generator working at 3 MHz. its resonant frequency, the crystal undergoes rapid mechanical oscillations, generating ultrasonic waves. These waves can propagate through the liquid in the vessel, creating effects like cavitation, acoustic streaming, or enhanced mixing.

The ultrasonic velocity (U) was determined using the following formula:

U = λ. f (1)

Viscosity: An experimental setup for measuring the viscosity by Ostwald viscometer. The viscometer was calibrated using distilled water at 298.15 K, and multiple measurements (five repetitions) were taken for each sample to ensure accuracy. The uncertainty in viscosity measurement is given as ± 0.005 × 10⁻³ mPa·s, indicating high precision.

Calculation of molar volume (V_m) and deviation in molar volume ( $V_m^E$) for liquid mixtures of cyclic diether with primary alcohols at experimental temperature using experimental density values (ρ). These values reported in Table 2 and Table 3 . As the mole fraction of cyclic diether (X₁) increases, molar volume (Vm) decreases for all binary mixtures. This suggests that 1,3-Dioxolane molecules may be filling the voids between alcohol molecules. The reduction in molar volume often points to dipole-induced dipole interactions, where the presence of 1,3-Dioxolane alters the hydrogen bonding network of the alcohols.

These positive values of $V_m^E$ are indicate volume expansion upon mixing. This suggests that intermolecular interactions are weaker in the pure components. The hydrogen bonds in primary alcohols are break and the formation of new, but weaker dipole-induced dipole interactions with 1,3-Dioxolane contribute to positive excess molar volumes. The physical contributions comparing of dispersive forces or weak dipole-dipole interaction lead to positive $V_m^E$ values. Chemical contributions include breaking up of associate present in pure liquids resulting in positive $V_m^E$ and specific interaction like formation of strong hydrogen bonds, charge-transfer complex and other complex forming interactions including strong dipole-dipole interaction between component molecules. The trend is consistent across all liquid mixtures. From Marcus [23] , alkanols molecules are joined by hydrogen bonding in pure liquid state ( Figure 1 ). The graphical analysis of ( $V_m^E$) vs. X₁ in Figure 2 should exhibit a positive deviation, possibly showing a peak, indicating the strongest deviation at a particular composition. This behavior highlights that molecular interactions change non-linearly with composition.

The deviation of adiabatic compressibility ( ${\beta }_{ad}^E$) of liquid mixtures provides valuable insights into the intermolecular interactions between cyclic diether and primary alcohols at experimental temperature. When excess adiabatic compressibility ( ${\beta }_{ad}^E$) values is positive. This suggests that weaker intermolecular forces (such as dipole-induced dipole interactions) dominate over stronger hydrogen bonds. When excess adiabatic compressibility ( ${\beta }_{ad}^E$) values is negative [24] then, the mixture is less compressible than expected. This indicates stronger molecular interactions. Tighter molecular packing reduces compressibility [25] . When considering excess adiabatic compressibility ( ${\beta }_{ad}^E$), then it is known that contributions heptanol, octanol, nonanol and decanol gives positive values, while pentanol and hexanol contribute negative values. Having in mind the various contributions operating in the studied systems, then the positive values of excess adiabatic compressibility ( ${\beta }_{ad}^E$), in Figure 3 can be attributed mainly to the disruption of the H-bonded structures as the alkanol molecule. The negative values of excess adiabatic compressibility ( ${\beta }_{ad}^E$), in the lack of c-atom region indicate that complex formation occurred through π… HO bonding between the π electron cloud of the aromatic ring of 1,3-dioxolane and the hydroxyl group of alkanol.

The excess adiabatic compressibility ( ${\beta }_{ad}^E$) values of 1,3-dioxolane and primary alkanols is insightful or aligns well with molecular interaction principles. When excess adiabatic compressibility ( ${\beta }_{ad}^E$) is negative, it shows that the experimental liquid mixture is less compressible from ideal mixing. When excess adiabatic compressibility ( ${\beta }_{ad}^E$) values is positive, it means the mixture is more compressible than expected. This occurs when dispersion forces (van der Waals interactions) dominate over specific hydrogen bonding, leading to: (1) Weaker inter molecular forces in the mixture than in pure components. (2) Increased free volume and looser packing, allowing the liquid to be more compressible. (3) Possible disruption of alcohol-alcohol hydrogen bonding without strong alternative interactions.

The excess adiabatic compressibility ( ${\beta }_{ad}^E$) values of 1,3-Dioxolane with alcohols are expected to follow a trend based on the strength of intermolecular interactions and molecular packing efficiency. Given your previous observations values of ( ${\beta }_{ad}^E)$ negative or positive, order is reflected to relative dominance of dipole-dipole interactions, hydrogen bonding, and dispersion forces in each binary mixture.

Since shorter alcohols have stronger hydrogen bonding interactions, leading to more negative ( ${\beta }_{ad}^E$) and longer alcohols exhibit increased dispersion forces, leading to more positive ( ${\beta }_{ad}^E$).

A deviation in viscosity (η^E) of 1,3-dioxolane + n-alkanol of liquid mixtures at experimental temperature are important for understanding molecular interactions in these systems. Based on Edward Peters’ principle, higher density or viscosity reflects stronger intermolecular interactions. A perusal of Figure 4 show that the excess viscosity (η^E) is negative for all prepared liquid mixtures at experimental temperature. The excess viscosity (η^E) can be positive or negative. Negative excess viscosity (η^E < 0), implies weaker interactions. It suggests the disruption of alcohol-alcohol hydrogen bonding by 1,3-dioxolane molecules, leading to lower resistance to flow and decreased viscosity.

An specific impedance (Z) of liquid mixtures investigated in this study showed either positive or negative at experimental temperature. These values are presented in Table 3 and Figure 5 . A perusal of Table 3 indicates the specific acoustic impedance (Z) values of all liquid are decrease but the increase in the mole fraction of dicyclic ether (X₁).

Figure 4 illustrates the differences of excess specific acoustic impedance (Z) for six binary liquid mixtures, A perusal of Figure 4 indicates the values of acoustic impedance (Z) is negative for all experimental liquid mixtures at experimental temperature.