CHEM 1A Lecture Notes - Lecture 9: Weak Base

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?

3. Write the product formed in the following reactions in the space provided. If the reaction does not take place write NO RXN. Indicate physical states by (s), (l), (g), (aq). Make sure the reaction is balanced! Please write the net ionic equation below.

a. Pb(CH₃CO₂)_2(aq) + Na₂SO_4(aq) Ã

b. AgNO_3(aq) + NH₄Br_(aq) Ã

4. Balance the following reactions and answer the questions below.

a. Al_(s) + HCl _(aq) Ã AlCl₃ + H₂

What is the element that is oxidized _______________________

What is the element that is reduced _______________________

Which compound is the oxidizing agent ____________________

Which compound is the reducing agent ____________________

b. Na_(s) + FeCl₂ Ã NaCl + Fe

What is the element that is oxidized _______________________

What is the element that is reduced _______________________

Which compound is the oxidizing agent ____________________

Which compound is the reducing agent ____________________

8. Using the unbalanced equation how many grams of lithium nitrate will be needed to make 250g of lithium sulfate, assuming that you have an adequate amount of lead (IV) sulfate to do the reaction.

Pb(SO₄)_2(aq) + LiNO_3(aq) Ã Pb(NO₃)_4(s) + Li₂SO_4(aq)

9. Using the following equation determine how many grams of sodium fluoride can react with 184.4 grams of magnesium.

Mg + NaF₂ Ã MgF₂ + Na

10. Determine how many Oxygen atoms are present in 46.7g of Zr(SO₄)₂

10. Given the following unbalanced equation:

Al₂O_3(aq) + Fe_(s) Ã Fe₂O_3(aq) + Al_(s)

Determine how many grams of Iron (III) Oxide can be formed if 224 grams of aluminum oxide is reacted with iron.

Multiple choice:

10b. Which of the following statement is true about 1 mole of Ca(NO₃)₂?

a. It contains the 6.02 x 10²³ NO₃^- ions.

b. It weighs 146 grams

c. It will most likely dissolve in a bucket of water.

d. It will produce equal number of Ca⁺² and NO₃^- ion in a solution.

10. How many molecules are present in 48.0 grams of oxygen gas? (O₂)

a. 6.02 x10²³ b. 1.81 x10²⁴ c. 9.03 x10²³ d. 1.03x10²⁴

12. If there are 12 moles of carbon in 1 mole of sucrose, C₁₂H₂₂O_11.How many atoms of carbon are there in 1 mole of sucrose?

a. 1 x6.03 x 10²³ b. 12x 6.03 x 10²³ c. 22 x 6.03 x 10²³

13. Determine the oxidation state of oxygen in the compound Cr₂O₃ in the following equation:

Cr₂O_3(s) + 2Al_(s) Ã Cr_(s) + Al₂O_3(s)

-2 b. -6 c. 6 d. 2

16. Determine the oxidation state of Al in the following equation:

Al_(s) + HCl à AlCl_3(aq) + H₂

+2 b. 0 c. +3 d. -5