Chemistry 1301A/B Study Guide - Final Guide: Zirconium, Royal Aircraft Factory F.E.2

1-How many grams of NaCl would be needed to prepare 150.00 L of a 1.402 M NaCl solution?

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2- first a standardized solution of sodium hydroxide (NaOH) will be quantitatively diluted to about 0.1 M but not exactly 0.1M. The molarity of the dilute NaOH will be calculated! A similar quantitative dilution was done in experiment 3 when you diluted 5.0 M HCl to 0.50M HCl using a volumetric flask and pipet.

The second part of the experiment is very similar to the last part of experiment 6 where samples of the unknown were weighed out, dissolved in water, and titrated with the dilute NaOH using phenolphthalein as the indicator to determine the percent by mass of a compound in the unknown. The compound will be different than the compound used in experiment 6. The molecular formula of the compound will be provided during the final. You must know how to weigh by difference (Preweigh, tare sample and small container to zero, transfer sample to flask, and place the small container back on balance to get mass) and titrate the sample using the buret in order to do well.

Be sure to read the instructions for the practical toward the end the CHM151L lab manual and do the practice problem on the next page.

You will have 1.5 hours to do the practical. You may only use a calculator and a pencil on the practical. There is no talking during the practical such that students cannot help each other and the TA may only help you with equipment problems.

It would be a good idea to wash any glassware you might use the lab period before the lab practical. There will also be a help session before the lab practical.

At the end of the lab final you will wash all glassware used or any dirty glassware in your locker, wash your unknown vials and remove the labels, checkin your locker and return your key, and evaluate the lab.

Please put the following statements in the correct order relating to the day of the lab practical:
1 2 3 4 5 6 Wash all your glassware and unknown vials, checkin your locker, evaluate the lab, and check your grades.
1 2 3 4 5 6 Do at least 3 good trials (weigh and titrate sample) as time allows.
1 2 3 4 5 6 Start the lab practical by diluting the NaOH solution.
1 2 3 4 5 6 Before the day of the practical clean glassware, read the practical instructions and do the practice problem in the lab manual and complete the loncapa problems for the final.
1 2 3 4 5 6 Calculate the molarity of the dilute NaOH, the percent by mass of the compound in you unknown for each trial and then the median.
1 2 3 4 5 6 Come to the help session before the lab final.

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3-

A NaOH solution was prepared by diluting 5.00 mL of 2.205 M NaOH to a final total volume of 100.00 mL. What is the exact molarity of the dilute NaOH (use 4-5 significant figures)?

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4-For the problem above, select glassware and size from the list below to conduct the dilution.

A B C D E F G H <= Glassware used to transfer the 2.205 M NaOH to be diluted
A B C D E F G H <= Glassware used to measure the final volume of the diluted M NaOH.

5 10 15 20 25 50 100 250 500 1000 <= Volume of the glassware chosen to transfer the concentrated NaOH above
5 10 15 20 25 50 100 250 500 1000 <= Volume of the glassware chosen to contain the final dilute NaOH above.

1a. The following algebraic equation:

(moles/L) x Z x grams/moles = grams

correctly solved for Z would be

a. Z = (moles/L) x grams/moles

b. Z = (L/moles) x grams/moles

c. Z = (grams) x (moles/grams) x (L/moles)

1b. Calculate the final mass in grams of Na3PO4 in a 5.00 M stock solution that is diluted from an initial volume of 25.0 mL to a final volume of 67.5 mL. Here's how you do it: Original concentration times its volume = number of moles present times F.W. = number of grams. These are also present in the diluted solution since you didn't add any more of the analyte, just water.

a. 163.94 g Na₃PO₄

b. 442.6 g Na₃PO₄

c. 20.49 g Na₃PO₄

1c. 10.00 g of Na₃PO₄ has how many grams of oxygen atoms in it?

a. 3.904 g O

b. 0.9760 g O

1d. Order the following solutions from the fewest number of moles of H+ per liter to the largest number of mole of H+ per liter.

0.75 M H3PO4

1.0 M nitric acid

1.0 M H2SO4

0.55 M H2SO4

1e. A tank of NH4Cl has a volume of 5000 gallons. If that solution's concentration is 0.7500 moles/L how many pounds of ammonium chloride does the tank contain?

a. 1673.7 pounds

b. 53.50 pounds

1f. Match the following:

number of moles of H2SO4 necessary to neutralize moles KOH

nitric acid moles to NaOH moles neutralization ratio

HCl to Ca(OH)2 neutralization ratio

KOH to H3PO4 neutralization ratio

E. 3:1

D. 1:2

C. 2:1

B. 1:1

A: 1:3

CHM111

Q1. Which of the following contains the MOST atoms? You shouldn't need to do a calculation here.

A) 10.0 g Ne

B) 10.0 g He

C) 10.0 g Ar

D) 10.0 g Kr

E) 10.0 g Mg

Q2. How many atoms are present in 0.23 moles of Calcium?

Q3. How many atoms are present in 5.6 mg of Silicon?

Q4. How many grams of iodine do 5.6 x 10²⁵ atoms of iodine represent?

Q5. Balance the following Chemical Equations:

_____ CaC₂(s) + _____H₂O(l) ? _____ Ca(OH)₂(aq) + _____ C₂H₂(g)

_____ P₄O₁₀ + _____ H₂O? ______ H₃PO₄

___ C₃H₈O₃ + ___ O₂ ? ___ CO₂ + ___ H₂O

_____ C₄H₁₀(l) + _____ O₂(g) ? _____ CO₂(g) + _____ H₂O(g)

___ Al + ___ N₂ ? ___ Al₂N₃

___ NaN₃ ? ___ Na + ___ N₂

___ C₃H₅N₃O₉ ? ___ CO₂ + ___ N₂ + ___ H₂O + ___ O₂

Q6. Calculate the percent composition of each element in Al(NO₃)₃

Q7. A 65.0 g sample of a pure compound containing only Nickel, Oxygen and Carbon is found to contain 22.36 g Nickel and 18.27 g Carbon. What is the empirical formula of compound?

Q8. Determine the Empirical formula and Molecular formula of a compound that contains: 65.4% C, 9.15% H and 25.4% N by mass and has a molar mass of 220 g/mol.

Q9. Oxygen gas can be produced by the decomposition of KClO₃

2KClO₃ (s) ? 2 KCl + 3 O₂ (g)

How many grams of O₂ can be produced from 1.625 g of KClO₃?

Q10. Consider the following balanced reaction: 2 Fe (s) + Al₂O₃ (s) ® 2 Al (s) + Fe₂O₃ (s)

If 6.25 moles of Fe react with 2.50 moles of Al₂O₃

Which reactant is the limiting reagent?

How many grams of Al are produced?

Q11. Consider the reaction for the manufacture of Aluminum sulfate:

2 AlCl₃ (aq) + 3 H₂SO₄ (aq) ? Al₂(SO₄)₃(aq) + 6 HCl (aq)

If 15.0 g of AlCl₃was mixed with 25.0 g of H₂SO₄, which reactant is the limiting reagent?

Calculate the theoretical yield of Al₂(SO₄)₃.

If only 18.63 g of Al₂(SO₄)₃ was produced, what is the percent yield of Al₂(SO₄)₃?

Q13. How many grams of Nickel (II) chloride are needed to prepare 100.0 ml of 0.125 M solution?

Q14. What volume of 0.125 M KMnO₄ (aq) solution can be prepared from 12.623 g of KMnO₄?