factorypolt.blogg.se - Chemlab hydrate formula

If the two weights disagree, you continue heating and weighing until you gets weights that agree. If the two weights are in agreement, then you are done heating. H 2O -> 0.43 g / 18.015 g/mol = 0.0239 molĬoCl 2 -> 0.01194 mol / 0.01194 mol = 1ĥ) How can you make sure that all of the water of hydration has been removed?Īfter weighing the anhydrous CoCl 2, you would continue to heat it. What is the formula for the original hydrate? How can you make sure that all of the water of hydration has been removed?Ģ) Determine moles of anhydrous CoCl 2 and H 2O:ĬoCl 2 -> 1.55 g / 129.839 g/mol = 0.01194 mol When cooled, the mass of the remaining dehydrated compound is found to be 1.55 g. Problem #4: A 1.98 g sample of a cobalt(II) chloride hydrate is heated over a burner. What is the value of n in the hydrate's formula?ġ) Calculate moles of anhydrous barium chloride: After heating, 4.26 g of anhydrous barium chloride, BaCl 2, remains.

nH 2O, is heated to drive off the water.

Problem #3: A 5.00 g sample of hydrated barium chloride, BaCl 2 The answers will not be exact but enough to tell the formula: What is the empirical formula?ġ) Assume 100 g of the compound is present, then find the moles of each:Ģ) Divide the smallest number into the others. Problem #2: A substance was found to have the following percentages by mass: 23% zinc 11% sulfur 22% oxygen 44% water. What hydrate is it?ġ) The amount of water in the hydrate is:Ģ) The moles of anhydrous LiClO 4 and water are: The mass of the hydrated salt obtained was 7.21 g. Care was taken to isolate all the lithium perchlorate as its hydrate. Problem #1: Anhydrous lithium perchlorate (4.78 g) was dissolved in water and re-crystalized. Your instructor/TA will use them to come up with a final experimental protocol that you will be using during the next lab period.ChemTeam: Determine the formula of a hydrate: ten problemsĭetermine the formula of a hydrate: ten problems Fifteen examples Calculate empirical formula when given mass data Fifteen problems Calculate empirical formula when given percent composition data A list of all the problems Determine identity of an element from a binary formula and a percent composition Mole Table of Contents Determine identity of an element from a binary formula and mass data

Delivers the presentation to te instructor/TA and the rest of the classĭon't forget to submit your proposal.

Responsible for writing the presentation of the proposal.

Spokesperson (Optional, for groups with 5 students) Leads the team in analyzing the data and the experimental error.Leads the team in developing experimental procedures.Leads the team in developing the theoretical foundations of the science behind the experiment.Responsible for formulating the purpose and the goal of the experiment.Validates group members have the supplies.Responsible for the Safety component in all aspects of the experiment.Responsible for ensuring that all team members are present and actively participating according to their roles.Roles will rotate from lab to lab in alphabetical order. Insufficient heating to cause all water to escape (how do you determine the process is complete?)Įach member of your team will have a role for the experimental design assignment.

Spattering of sample upon heating as water escapes from hydrated salt.Humidity, water adsorbed to surface materials.Parameters you need to account for in your proposal: You can substitute aluminum pie pans for aluminum foil. \( \newcommand\]įor your experiment design use the supplies mentioned above.