A low-cost and simple setup to measure the densities of liquids is introduced herein. The results and reliability of this setup were evaluated for pure liquids, water-ethanol binary mixtures, and aqueous NaCl solutions. The constructed densitometer provided density values with acceptable relative errors (less than ±3.0%), which were compared to…

In this organic chemistry laboratory experiment, students are guided through a series of exercises to understand the behavior of compounds during liquid-liquid extraction. Aspects of density, structure, solubility, acid-base theory, and pK[subscript a] are all incorporated into activities that students complete in groups. After using their initial…

An activity is described wherein students observe dynamic floating and sinking behavior of plastic pieces in various liquids. The liquids and solids are all contained within a plastic bottle; the entire assembly is called a "density bottle". After completing a series of experiments that guides students to think about the relative…

In this experiment, physical science students measured the mass of several soda cans, measured the mass and volume of water displaced when these cans were placed in water, and determined whether these cans sank or floated in water. Then, the students plotted graphs of the mass of displaced water versus the volume of displaced water, the mass of…

Any student that has spent time in the kitchen knows that hot vegetable oil will pop and spatter violently after coming into contact with water such as that on the surface of foods (meat, fish, potatoes, etc.). This well-known effect can be used as an instructional resource to promote cooperative, active, and inquiry-based learning about central…

Herein, we describe an accessible and safe organic chemistry lab experiment that can be completed at home. Liquid-liquid extraction is a fundamental organic chemistry lab experiment that touches on topics such as chemical structure, density, solubility, and acid-base chemistry. Given the increased demand for safe organic chemistry experiments that…

Describes a demonstration on the density of the liquids water and ethanol and the solubility of air in those liquids. Also includes a related demonstration using Styrofoam balls. (DKM)

Describes a demonstration which creates the illusion of violating Archimedes Principle. The procedure involves two liquids with identical densities and produces drops of one liquid suspended in the middle of a column of the second liquid. (DDR)

For most materials, the solid at and near the triple-point temperature is denser than the liquid with which it is in equilibrium. However, for water and certain other materials, the densities of the phases are reversed, with the solid being less dense. The profound consequences for the appearance of the "pVT" diagram of one-component materials…

Procedures for preparing density gradient columns for chemical displays are presented. They include displays illustrating acid-base reactions, metal ion equilibria, and liquid density. The lifetime of these metastable displays is surprising, some lasting for months in display cabinets. (JN)

A simple experiment, the determination of the density of a liquid by several methods, is presented. Since the concept of density is a familiar one, the experiment is suitable for the introductory laboratory period of a first- or second-year course in physical or analytical chemistry. The main objective of the experiment is to familiarize students…

Outlines experiments in which a density gradient might be used to advantage. A density gradient consists of a column of liquid, the composition and density of which varies along its length. The procedure can be used in analysis of solutions and mixtures and in density measures of solids. (Author/TS)

A safe and inexpensive laboratory for a first-year general chemistry course has been developed which allows students to explore important properties of carbon dioxide, particularly its behavior as a greenhouse gas. Students witness and measure air displacement to compare calculated gas densities and pressures inside a CO[subscript 2]-filled…

All-solid-state polymer electrolytes (SPEs) have been regarded as an advisible alternative for simultaneously overcoming the safety issues and high energy density demands presented in traditional lithium batteries, and they represent the development orientation of energy storage devices. This course describes the preparation of a cross-linked and…

We propose an in silico experiment to introduce the classical density functional theory (cDFT). Density functional theories, whether quantum or classical, rely on abstract concepts that are nonintuitive; however, they are at the heart of powerful tools and active fields of research in both physics and chemistry. They led to the 1998 Nobel Prize in…