nheptane

n-Heptane, or normal heptane, is the straight-chain alkane with seven carbon atoms, chemical formula C7H16. It is a colorless, volatile liquid at room temperature and pressure. As a nonpolar hydrocarbon, it is insoluble in water and miscible with many organic solvents. It is one of several C7 hydrocarbons produced during crude oil refining.

Physical properties include a boiling point of about 98 °C and a melting point near −91 °C. Its density is roughly 0.684 g/mL at 20 °C. It has a relatively high vapor pressure for a hydrocarbon at room temperature and evaporates readily. It is flammable, and its vapors can form explosive mixtures with air.

Production and occurrence: n-Heptane occurs in the n-alkane fraction obtained from petroleum and natural gas liquids. It is typically purified by distillation and purification steps to remove impurities before use as a solvent or reference material.

Uses: It serves as a nonpolar solvent in laboratories and industry and is used as a calibration or reference component in gas chromatography. In fuel chemistry, n-heptane is used as a zero-reference component for octane rating, with iso-octane (2,2,4-trimethylpentane) given the value 100 on the octane scale.

Safety and handling: n-Heptane is flammable; vapors can travel and ignite. Inhalation may cause dizziness or drowsiness, and skin or eye exposure can cause irritation. Use in well-ventilated areas, avoid ignition sources, and store in tightly closed containers away from oxidizers. Spills should be contained and collected, and disposal must follow local regulations.