What is your sample number?
Abracadabra
Ex.
We didn't have one so he said to put whatever you want.
a) What volume of H C l was needed to dissolve the tablet for Trial 1? Show your work with proper significant figures and units. Show numbers with descriptors. For example 23.00 mL (Final Vol H C l) - 0.50 mL (Init Vol H C l) = 22.50 mL
b) What volume of N a O H was needed to react with excess H C l for Trial 1? Show your work with proper significant figures and units. Show numbers with descriptors.
Volume of HCl needed to dissolve the tablet for Trial 1= 20.10 mL (Final Volume HCl) - 0.10 mL (Initial Volume HCl) = 20.00 mL HCl
Volume of NaOH needed to react with excess HCl for Trial 1= 15.20 mL (Final Volume NaOH) - 0.20 mL (Initial Volume NaOH) = 15.00 mL NaOH
a) How many moles of H C l was added to dissolve the tablet for Trial 1? Show your work with proper significant figures and units. Show numbers with short descriptors.
b) How many moles of N a O H was added to neutralize the excess H C l added in the back-titration for Trial 1? Show your work with proper significant figures and units. Show numbers with short descriptors.
Moles of HCl added to dissolve the tablet for Trial 1= 20.00 mL (Volume of HCl) x ( 1 L / 1000 mL (conversion to liters)) x (0.2517 mol HCl / 1 L (molarity of HCl solution)) = 0.005034 mol HCl added
Moles of NaOH added to neutralize the excess HCl added in the back-titration for Trial 1= 15.00 mL (Volume of NaOH) x ( 1 L / 1000 mL (conversion to liters)) x (0.2704 mol HCl / 1 L (molarity of NaOH solution)) = 0.004056 mol NaOH added = mol HCl excess
a) How many moles of H C l were neutralized by the tablet for Trial 1?
b) How many moles of C a CO3 did the tablet contain?
c) How many grams of C a CO3 did the tablet contain?
Show your work with the proper number of significant figures and units.
Moles of HCl neutralized by the tablet for Trial 1= 0.005034 mol (mole of HCl) - 0.004056 mol (mole of NaOH) = 0.000978 mol HCl neutralized by tablet
Moles of CaCO3 the tablet contain= 0.00978 mol (mole HCl neutralized by tablet) x (1 mol CaCO3 / 2 mol HCl (mole ratio)) = 0.000489 mol CaCO3
Grams of CaCO3 the tablet contain= 0.00489 mol (mole of CaCO3) x (100.09 g (grams of CaCO3) / 1 mol CaCO3) = 0.0489 g CaCO3
a) What is the mass of your antacid power used in trial 1?
b) What is the percent mass of C a CO3 for trial 1? Show your work with proper units and significant figures. Show numbers with short descriptors.
c) What was your percent C a CO3 in trial 2 (and any additional trials performed)?
d) What is the average percent C a CO3 for all trials? Show work.
Mass of antacid powder used in trial 1= 0.1068 g (grams of antacid power)
Percent mass of CaCO3 for trial 1= (0.0489 g (grams of CaCO3) / 0.1068 g (grams of antacid powder)) x 100 = 45.8% of CaCO3 for trial 1
Percent CaCO3 in trial 2= (0.0449 g (grams of CaCO3) / 0.1070 g (grams of antacid powder)) x 100 = 42.0% of CaCO3 for trial 2
Average percent CaCO3 for all trials= (45.8 (percent mass of CaCO3 for trial 1) + 42.0 (percent mass of CaCO3 for trial 2)) / 2 (number of trials) = 43.9% average percent CaCO3
Your instructor will give you instructions as what to do with this box. It may be used for bonus points, or for taking away points (for example late submissions) or for error analysis if something went wrong during the lab. If no instructions have been provided to you, please leave this box blank.
5% = 5
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