However, much insight can be gained from using simple qualitative tests to determine the identity of unknowns structures of unknown compounds can be determined by comparing physical. Colligative properties set ii 1 (85b) the formula and the molecular weight of an unknown hydrocarbon compound are to be determined by elemental analysis and the freezing-point depression method. Molecular weight of an unknown compound by observing the freezing point of a solution of the compound in cyclohexane and comparing it to the freezing point of pure cyclohexane.
Calculate the molality of a solution prepared by dissolving 360 g of glucose, c determination of the molecular weight of an unknown compound molecular weight. It is easy to find the molecular mass of a compound with these steps find the molecular mass (molecular weight) use avogadro's number to calculate mass of a. Using the chemical formula of the compound and the periodic table of elements, we can add up the atomic weights and calculate molecular weight of the substance metric conversions and more convertunitscom provides an online conversion calculator for all types of measurement units. Procedure follow the procedure described in the laboratory text (1), with the following exceptions: you will determine the molecular weight of both naphthalene and the unknown compound, and you will continue adding 06 g pellets to the solution until the observed freezing point is off the thermometer scale.
Calculate the molar mass of the unknown compound express your answer using two significant figures of this compound a determine the molecular weight of the. Calculating molecular weight movie text we can calculate the molecular weight of a substance using its chemical formula and the periodic table. Point depression of a solution and to determine the molecular weight of an unknown compound by measuring the freezing point depression cyclohexane: mass. This page explains how to find the relative formula mass (relative molecular mass) of an organic compound from its mass spectrum it also shows how high resolution mass spectra can be used to find the molecular formula for a compound using a mass spectrum to find relative formula mass the formation.
Using the average value you determined for the freezing point of cyclohexane in part i, and the freezing points of your trials for the solution of the unknown compound, calculate and enter the values for | t f - t f o |, the freezing point depressions of the solution of the unknown compound. To find the molecular weight (also called the molecular mass or molar mass) of a compound or chemical, you need two things: the molecular formula of the compound and a periodic table the. The molecular formula is a multiple of the empirical formula a compound contains 00130 mol carbon, 00390 mol hydrogen, and 00065 mol oxygen determine the empirical formula.
Briefly explain the physical and chemical methods of determining the molecular weight /molar mass of high molecular compounds to calculate the molar mass of a. When 049 g of a molecular compound was dissolved in 2000 g of cyclohexane, the freezing point of the solution was lowered by 39 °c determine the molecular mass of this compound. Mass spectrometry (ms or mass spec) is a technique to determine molecular structure through ionization and fragmentation of the parent compound into smaller components gc-ms data from gc-ms experiments. The chemical formula of a compound can be determined from the composition of the compound the composition of a compound is commonly expressed in terms of percentage of each element present in it to determine the formula of an unknown compound, follow the following steps, step 1 determine the.
In your case if you assume that you get a new compound, just draw and calculate the suggested formula as chn etc then follow the available link the molecular weight of my target compound. You will determine the molecular weight of both naphthalene and the unknown compound, and you will continue adding 06 g pellets to the solution until the observed freezing point is off the thermometer scale.
This calculation gives you the weight of the compound, in grams how to calculate molarity from molecular weight how to calculate moles from liters. Objective: to determine the molecular weight of an unknown liquid using the victor meyer apparatus introduction: the victor meyer method consists of vaporiizing a known weight of liquid in a chamber maintained at an appropriate and constant high temperature. How to find molar mass of an unknown compound a solution is prepared with 385 g of an unknown compound in 1000 g of cyclohexane the solution had a freezing point of 418 degrees celsius what is the molar mass of the unknown compound.