Quimica Inorganica

CARACTERIZACIÓN DE LOS INSTRUMENTOS DEL LABORATORIO, Y MEDIDAS DE MASA, VOLUMEN Y DENSIDAD

CHARACTERIZATION OF LABORATORY INSTRUMENTS AND MEASUREMENTS OF MASS, VOLUME AND DENSITY.

Puerto. Sebastian* Echeverry. David, Rincón. Yeimy, Molina. Sara.

* Correspondence Author: juanpuertot@usantotomas.edu.co

Universidad Santo Tomas- Villavicencio 2A. Facultad de Ingeniería Ambiental.

RESUMEN

Identificar y observar las características de los diferentes instrumentos que se usan en el laboratorio teniendo en cuenta aspectos como, utilidad, exactitud y funcionamiento a la hora de la práctica, en este caso cuando se toman medidas como, masa, volumen y densidad. Es importante conocer sobre el funcionamiento de los instrumentos ya que ayuda a tomar correctamente datos y desarrollar un buen trabajo en el laboratorio.

Palabras claves: Laboratorio, materiales, masa, volumen y densidad.

ABSTRACT

Identify and observe the characteristics of the various instruments used in the laboratory taking into account aspects such as utility, accuracy and performance when it comes to practice, in this case when measures as mass, volume and density are taken. It is important to know about the operation of instruments and helps properly take data and develop a good work in the laboratory.

Keywords: Laboratory, materials, mass, volume, density.

INTRODUCCIÓN

En el laboratorio de química es vital la caracterización y reconocimiento de los instrumentos de laboratorio, medidas de masa (medida de cantidad que posee un cuerpo), volumen (cantidad de espacio tridimensional que ocupa un objeto) y densidad (cuanto material se encuentra comprimido en un espacio determinado), ayudando a despejar dudas sobre conceptos básicos y manipulación correcta de los instrumentos de laboratorio.

El trabajo de laboratorio inició con la observación y reconocimiento de los materiales y algunos reactivos que se encuentran allí, posteriormente se tomaron medidas de masa (con monedas) y volumen (con agua y algunos líquidos asignados), a continuación se determinó la densidad de una puntilla de cobre y por último se observó el cambio de color de la llama cuando se ponen en el fuego de un mechero diferentes materiales, todo como parte de un proceso general de examinar los implementos diseñados para cada función específica.

OBJETIVOS

Analizar la llama de una vela.

Comparar la medición de volúmenes en sus respectivos equipos para determinar la exactitud y precisión de cada una.

Determinar la densidad de un líquido.

Conocer los términos que están asociados al tratamiento específico de datos.

Reconocer las diferentes clases de material de laboratorio, equipos y reactivos para su adecuado manejo y disposición.

Familiarizarse con el equipo de laboratorio de uso corriente.

MARCO TEORICO

In a chemical laboratory, various types of apparatus are necessary to perform a variety of experiments. Laboratory apparatus are often made of glass, ceramic or metal and are used for measuring the volume of solutions and for mixing, heating and storing mixtures, among other tasks. Knowing the apparatus found in a chemistry laboratory is important to technicians and chemistry students. (Zinni,2014)

Measuring: Some glassware apparatus is used to store but also measure the volume of liquids they keep. A pipette is a long tube use for measuring and transferring small quantities of liquids from one flask to the other. A cylindrical glass container with a beak in the upper side to help pour the liquid from one container to the next is a beaker, which is available in various sizes, such as 50 ml and 500 ml. The measuring cylinder is a glass cylinder with graduating marks while a burette is a type of measuring cylinder with a tap at the lower end. ( Zinni,2014)

Heating: A Bunsen burner is a heating device made of a metallic base and a fitted gas tube and is used for heating and sterilizing. The isomantle, or heating mantle, is an electrical apparatus used to heat the substance contained in a glass container while the electrical hot plate is an alternative to the Bunsen burner. A cup-shaped container often made of ceramic used to heat substances at high temperatures is a crucible. ( Zinni,2014)

Mixing and Storing: A flat-bottom glass cone used for mixing and storing substances is an Erlenmeyer flash, which is also used when heating with a Bunsen burner. Test tubes are glass tubes of various sizes, which are often kept in a stand or rack made of wood or plastic. Reagent bottles have very small openings and are primarily used to store chemical substances used during the experiments. (Zinni, 2014)

Other Apparatus: The Buchner funnel has a cylindrical upper portion and a conical lower base with a steam pipe. It is often made of porcelain and used in various filtering processes. A metal support to keep round-bottom glass flasks and funnels while heating with a Bunsen burner is a ring stand. Metal tripods are used with flat-bottom flasks. Stir rods have the shape of drinking straws and are made of solid glass and used to stir mixtures. A small glass bowl used to hold solids while they are weighed or transported is a watch glass. (Zinni, 2014)

The Mass (symbolized m ) is a dimensionless quantity representing the amount of matter in a particle or object. The standard unit of mass in the International System ( SI ) is the kilogram ( kg ). (Beran, 2010).

Weight is the force exerted by a mass under the influence of gravity: weight (W) = mass (m) x gravitational acceleration (g). The mass of a particular object is a fixed quantity, but acceleration due to gravity, and therefore weight, varies with location. (Beran, 2010).

Volume is the quantity of three-dimensional space occupied by a liquid, solid, or gas. Common units used to express volume include liters, cubic meters, gallons, milliliters, teaspoons and ounces. Many other units exist. For find volume there are those equations: L*L*L= V3, V= M/D or V = π.r2.h. (Roberts,2012).

Density is a physical characteristic of a material. It is a measure of the mass per unit of volume of that substance under specified conditions of pressure and temperature. (Computing Uncertainties in Laboratory Data and Result, 2010)

Density is mass per unit volume. "Per" means in one, and "unit volume" means someone pick a unit of measurement for the volume. Mass, again, has several units to be used. If someone measure the mass in grams and the volume in milliliters then divide to find the mass of one milliliter that gives the mass per unit (1) volume or basically D= M/V. (Computing Uncertainties in Laboratory Data and Result, 2010)

One of the elements of laboratory is a precision

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