CH13 MOLARITY/MOLALITY LAB NAME_________________PD___
PURPOSE: Calculate molarity , molality, and % error from lab data, and prepare solutions of given concentration
PROCEDURE: Use drying ovens to evaporate water from solutions, and volumetric flasks to prepare solutions in manner described by the instructor. *SHOW WORK
DATA:
PART 1 saltwater sodium sulfate solution
formula
Mass e dish
Mass e dish & solution
Volume of solution
Mass e dish & solute
Actual molarity
Actual molality
CALCULATIONS
PART 1
Mass solute
*Moles solute
*SHOW WORK
Liters of solution
*Experimental molarity
*SHOW WORK
*% error molarity
*SHOW WORK
mass of water (solvent) in g
mass of water in Kg
*experimental molality
*SHOW WORK
*% error molality
*SHOW WORK
CONCLUSIONS
Describe the crystals
What was the purpose of the oven?
Fill in the blanks with general terms from this chapter. We put _______ into the oven, the oven removed the _________ ,and we took __________ out of the oven.
To find molarity divide _______ of __________ by ___________ of ________. To find molality, divide __________ of ___________ by ___________ of ____________.
To find % error, subtract ___________ from ___________ , then divide by _____________and multiply by __________
Magic marker is insoluble in __________ but is soluble in ____________.
stopped here may 2018
PART 2 MAKING SOLUTIONS
VOLUME CONCENTRATION *MASS OF SOLUTE NEEDED
1000mL 0.030M calcium chloride
SHOW WORK
250mL 0.051M sodium sulfate
SHOW WORK
50mL 0.060M lead (II) nitrate*
SHOW WORK
250mL 0.055M potassium iodide*
SHOW WORK
250mL 1.30M potassium chloride*
SHOW WORK
500mL 0.048 M sodium phosphate
SHOW WORK
Fill in form. class data available later
___________________________
EXPLAIN HOW THE SOLUTION Will be MADE: When making solutions, first calculate the _________ mass by using the formula. Then calculate the moles of _________ needed by multiplying the __________ by the volume of ____________ (in L). Then convert the moles into mass of _______ needed to make the solutions. Mass it on the balance, then put it in the __________ flask. Add __________ water until the ___________ comes up to the line. Invert the flask several times, and add the last bit of water with a ___________.
DESCRIBE SOME ERRORS LIKELY TO BE MADE WHEN MAKING SOLUTIONS