CHEM 10 Lecture Notes - Lecture 7: Sodium Bromide, Sodium Hydroxide, Potassium Iodide

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All chemical reactions can be placed into one of six categories.

Here they are, in no particular order:

1) Combustion: A combustion reaction is when oxygen combines with another

compound to form water and carbon dioxide. These reactions are exothermic,

meaning they produce heat. An example of this kind of reaction is the burning of

napthalene:

C10H8 + 12 O2 ---> 10 CO2 + 4 H2O

2) Synthesis: A synthesis reaction is when two or more simple compounds

combine to form a more complicated one. These reactions come in the general

form of:

A + B ---> AB

One example of a synthesis reaction is the combination of iron and sulfur to form

iron (II) sulfide:

8 Fe + S8 ---> 8 FeS

3) Decomposition: A decomposition reaction is the opposite of a synthesis

reaction - a complex molecule breaks down to make simpler ones. These

reactions come in the general form:

AB ---> A + B

One example of a decomposition reaction is the electrolysis of water to make

oxygen and hydrogen gas:

2 H2O ---> 2 H2 + O2

4) Single displacement: This is when one element trades places with another

element in a compound. These reactions come in the general form of:

A + BC ---> AC + B

One example of a single displacement reaction is when magnesium replaces

hydrogen in water to make magnesium hydroxide and hydrogen gas:

Mg + 2 H2O ---> Mg(OH)2 + H2

5) Double displacement: This is when the anions and cations of two different

molecules switch places, forming two entirely different compounds. These

reactions are in the general form:

AB + CD ---> AD + CB

One example of a double displacement reaction is the reaction of lead (II) nitrate

with potassium iodide to form lead (II) iodide and potassium nitrate:

Pb(NO3)2 + 2 KI ---> PbI2 + 2 KNO3

6) Acid-base: This is a special kind of double displacement reaction that takes

place when an acid and base react with each other. The H+ ion in the acid reacts

with the OH- ion in the base, causing the formation of water. Generally, the

product of this reaction is some ionic salt and water:

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Document Summary

All chemical reactions can be placed into one of six categories. Here they are, in no particular order: combustion: a combustion reaction is when oxygen combines with another compound to form water and carbon dioxide. These reactions are exothermic, meaning they produce heat. An example of this kind of reaction is the burning of napthalene: C10h8 + 12 o2 ---> 10 co2 + 4 h2o: synthesis: a synthesis reaction is when two or more simple compounds combine to form a more complicated one. One example of a synthesis reaction is the combination of iron and sulfur to form iron (ii) sulfide: 8 fe + s8 ---> 8 fes: decomposition: a decomposition reaction is the opposite of a synthesis reaction - a complex molecule breaks down to make simpler ones. One example of a decomposition reaction is the electrolysis of water to make oxygen and hydrogen gas:

Related Questions

HERE IS HOW THIS IS GOING TO WORK! IF YOU ANSWER THE QUESTIONS IWILL GIVE YOU THE 3K POINTS + MORE AFTER I REPOST IT.

2. The amount of heat involved in the synthesis of 1 mole of acompound from its elements, with all substances in their standardstates at 25*C, is called _________.

3. What is a valid unit for specific heat?

4. Use Hess's Law to find the heat of reaction in the examplebelow.

N2O4 (g) ----> 2NO2 (g)

Given that:

N2O4 (g) ----> N2 (g) + 2O2 (g) (Delta H =-9.7kJ)

2NO2 (g) ----> 2O2(g) + N2(g) ( Delta H= -67.7kJ)

5. Use Hess's Law to find the heat of reaction in the examplebelow. (Example doesn't exist btw.)

6. (Delta H) for the formation of rust (Fe2O3) is -826 kJ/mol. Howmuch energy is involved in the formation of 5 grams ofrust?

7. How many kilocalories of heat are required to raise thetemperature of 50g of aluminum from -5*C to 35*C? (Specific heat ofAluminum = 0.21 cal/g*C)

8.Calculate the (Delta H) for this reaction:

Zn(s) + Cu (2+ ion)(aq) ---> Zn(2+) + Cu(s)

(Delta H) for Cu(2+) = +64.4 kJ/Mol; (Delta H) for Zn(2+) = -152.4kJ/mol

9. The following equation shows the reaction that occurs whennitroglycerine explodes.

4C3H5O9N3 ----> 12CO2 + 6N2 + O2 +10H2O + 1725 Kcal

Is this reaction exothermic , endothermic, a combustion reaction ,or a combination reaction?

10. What does it mean for ammonia, (NH3) to have a (Delta H f) =-46 kJ/mol?

(for example: Define heat of formation. What does a negative heatof formation mean? what do the units of kJ/mol mean?)

11. What is the maximum amount of KCl that can dissolve in 500g ofwater?

(solubility of KCl is 34 g/ 100g of water at 20*C)

12.List the ways(operations) that can help make a substancedissolve faster in a solvent?

13. If a crystal added to an aqueous solution causes many particlesto come out of solution, the original solution was (saturate,unsaturated, supersaturated).

14. What is the number of moles of solute in 165 mL of a 0.82 Msolution?

15. What mass of NaCl is needed to make 350 mL of a 1.00 Msolution?

16. Colligative properties depend upon...

17. If one mole of each of these solutes in added to the sameamount of water, which solution has the highest boiling point?(glucose, aluminum sulfate, magnesium acetate, copper (I)chloride)

18. When an acid reacts with a base, what compounds areformed?

19. If the [H+] in a solution is 1x10^(-13) mol/L, what is the[OH-]?

20. If the [OH-] = 1x10^-6 mol/L, what is the pH of thesolution?

21. For a solution to be considered acidic what must be thehydrogen-ion concentration?

22. Which of the following represents a Bronsted-Lowry conjugateacid-base pair?

a) SO3(2-) and SO2 b) CO3(2-) and CO c) H3O and H2 d) NH4(+) and NH3

23. With solutions of "strong" acids and "strong" bases, the word"strong" refers to ...

24. What are the products of Al(OH)3 + H2CO3?

25.What is the concentration of hydrochloric acid if 5.0 mL of acidis neutralized by 30.0 mL of 2.00M sodium hydroxide.

26. At equilibrium, what is the rate of production of reactantscompared with the rate of production of products?

27. What is the equilibrium constant for the following reaction2SO3 ---> 2SO2 + O2

28. How does an increase in pressure affect the following reaction?2SO3 (g) --> 2SO2(g) +O2(g)

29.What stresses would shift the reaction to the right?

2SO3(g) ==> 2SO2(g) + O2(g)

30. The Keq of a reaction 4.9 x 10^(-7). Are products or reactantsfavored at equilibrium?

31. In which of these systems is the entropy decreasing?

a) air escaping from a tire b) snow melting c) a gas condensing d) salt dissolving inwater

32. If an atom is reduced in a redox reaction, what must occur toanother atom in the system?

33. Identify the oxidizing agent in the following reaction: 2Na + S---> Na2S

34. What are transferred in an oxidation -reductionreaction?

35. Give the oxidation number for each atom in KMnO4.

36. Which atom has a change in oxidation number of +4 in thefollowing reaction?

K2Cr2O7 + H2O + S ----> KOH + Cr2O3 +SO2

37. What is the oxidation number of sulfur in each of the following:

a. SO3 c.SO2(2-)

b. Na2SO4 d. S2O4 (2-)

38.Fe(3+) ----> Fe represents oxidation, reduction, orhydrolysis?

39. When the half reactions Br2+ 2e- -----> 2Br- and Na---->e- + Na(+) are combined the balanced redox equation is_____________________ ( WRITE the BALANCED REDOX eq)

40. To balance the oxygen and hydrogen for a redox reaction thattakes place in basic solution, it is necessary to use whichsubstance?

41. What particle completes this nuclear equation? 55/25 Mn + 2/1 H====> _____ +2 1/0 n

42. The half-life of tungsten-182 (182/74 W) is 1.1x10^(17) years.How long would it take for a 376.2 kg sample to decay until only123.0 grams remain?

43. After 3 days, the quantity of certain radioisotope is reducedfrom 13.6 grams to 1.9 grams. Calculate the half-life of theisotope.

44. What is the name of the compound having the formulaC8H18.

45. What is the name of the following compound:

CH3---CH2----CH---CH2--C

I \

CH3 OH

46. What is an isomer? Give an isomer of hexane (C6H14) and drawit's structure.

47. What is the name of the hydrocarbons with double covalentbonds?

48. Draw the stucture for 3-methylbutanoic acid.

49. Draw the structure for methylbenzene?

50. What is the name of the following compound:

CH3----C-----CH3

CH3

silverclam911

Decomposition of Malachite

Here is what Malachite is Made Out Of

Malachite is a famous and very popular semi-precious stone. Its banded light and dark green bands are one-of-a-kind, and give it a unique ornamental quality unlike that of any other stone. The light and dark green bands are so distinctive that malachite may be one of the most easily recognized minerals by the general public. Malachite is popular in jewelry, especially Native American southwestern jewelry. The stones inlayed in silver make a nice alternative to traditional turquoise jewelry.

Malachite is a form of copper carbonate with the molecular formula Cu₂CO₃(OH)₂. When heated to around 200 ï¿½C, malachite decomposes into copper (II) oxide (CuO) and other products.

Reaction Stoichiometry

The Law of Conservation of Mass states that matter can neither be created nor destroyed. Therefore, the number of atoms of each element on the reactants side must be same as the number of atoms on the products side. This quantitative study of chemical reactions is called stoichiometry. The substances in a balanced reaction are related to each other by stoichiometric molar ratios. For example, magnesium reacts with hydrochloric acid in a 1:2 stoichiometric ratio in the balanced equation below.

Mg(s) + 2HCl(aq) -> MgCl2(aq) + H2(g)

The molar ratios can be used as conversion factors to find the amount (in moles) of one substance given the amount of another. For example, given the number of moles of HCl, the amount of MgCl₂ can be determined as shown below.

nMgCl2=nHCl x (1mol MgCl2) / (2mol HCL)

The molar ratios are used to determine the amount in moles. However, the amount of reactant or product is often measured in grams. Mass can be converted to moles and vice versa as shown below.

n = m / (MM)

m = n x MM

where n is the number of moles, m is the mass of the product in g, and MM is its molar mass in g/mol.

To observe the Law of Conservation of Mass, you can perform different types of chemical reactions. For example, you can use a decomposition reaction to observe one compound being broken down into two or more elements or new compounds. For this reaction to take place, you must break existing bonds within the starting compound. Different sources of energy such as heat, light, or electricity may be used. Through a decomposition reaction, you can observe that the atoms in the original compound are not destroyed but are rearranged to form simpler substances, such as elements or compounds.

About This Lab

In this lab, you will test if the relationship between malachite and copper (II) oxide is stoichiometric. To do this, you will heat a known mass of malachite to produce copper (II) oxide. You will then compare the amount of copper (II) oxide obtained experimentally with the amount of copper (II) oxide expected from the balanced equation for the decomposition reaction.

1.Take a crucible from the Containers shelf and place it on the workbench.

2.Take a balance from the Instruments shelf and place it on the workbench.

3.Move the crucible onto the balance. Record the mass of the empty crucible to the nearest 0.001g in your Lab Notes.

4.Move the crucible onto the workbench.

5.Take copper (II) carbonate hydroxide from the Materials shelf and add 10 g to the crucible.

6.Move the crucible onto the balance and record the mass of the crucible containing copper (II) carbonate hydroxide in your Lab Notes.

7.Take a Bunsen burner from the Instruments shelf and place it on the workbench.

8.Move the crucible onto the Bunsen burner.

9.Double-click on the crucible to open its properties. Select Show Contents and click OK. This gives you a cut-away view of the crucible's contents.

10.Turn the Bunsen burner on to low flame by clicking the knob at the bottom once. Clicking multiple times will increase the intensity of the flame until it is turned off.

11.Watch the crucible until the malachite fully decomposes. You will see a distinct color change.

12.Move the crucible onto the workbench to cool.

13.Turn off your Bunsen burner.

14.Weigh the crucible with its contents and record the mass to the nearest 0.001 g in your Lab Notes.

Clear your station.

Lab Notes:

Numbers below refer to numbers in the above âAbout this Labâ

3. Empty crucible = 88 g

5. Added 10 g of Copper (II) carbonate hydroxide to crucible

6. Crucible with Copper (II) carbonate hydroxide = 98 g

11. to Black

14. after heating crucible with its contents = 95.195

Questions I have answered:

How many grams of malachite did you add to the crucible? 10g

How many grams of product were in the crucible after heating? 7.195

By how much did the mass of the crucible's contents change after heating? -2.805

The molar mass of malachite is 221.1 g/mol. How many moles of malachite were present before the reaction? 0.04523 mol

The product remaining in the crucible after heating is copper (II) oxide. The molar mass of copper (II) oxide is 79.55 g/mol. How many moles of copper (II) oxide were produced during the reaction?

0.0945 mol

Please answer the following:

Q1 a. Which of the following represents the balanced chemical equation for this reaction?

Cu2CO3(OH)2=2CuO+H2O

Cu2CO3(OH)2=CuO+CO2

Cu2CO3(OH)2=2CuO+H2O+CO2

Cu2CO3(OH)2=CuO+H2O+CO2

b. Based on the number of moles of malachite that you started with, how many grams of water were produced? The molar mass of water is 18.0153 g/mol. Choose the closest answer.

1.815 g 0.8148 g 1.630 g 1.982 g

c. Based on the number of moles of malachite that you started with, how many moles of CO₂were produced? Choose the closest answer.

1.000 mol 0.04523 mol 0.9000 mol 0.09045 mol

d. Based on the number of moles of malachite that you started with, how many grams of CO₂were produced? The molar mass of CO₂ is 44.01 g/mol. Choose the closest answer.

1.991 g 0.4401 g 0.04523 g 3.981 g

Q2a. Based on the number of grams of CO₂ and H₂O produced during the reaction, does this compensate for the observed loss of mass?

A. No, because this violates the law of conservation of mass

B. yes, this compensates for the mass lost in the reaction

C. No, because more copper oxide was produced

D. No because mass is conserved

b. You observed that the products in the crucible weigh less than the reactants that you added. How is this possible?

A. Mass was lost due to experimental error

B. The Malachite absorbed CO2 from the air

C. CO2 and H2O were released as gases

D. Mass was converted to energy

c. What kind of a reaction took place upon heating?

A. decomposition

B. single displacement

C. synthesis

D. Double displacement

d. Baking soda is used as a leavening agent in baking. When heated, baking soda undergoes a decomposition reaction to form carbon dioxide. Given the data below, which of the following reactions occurs during baking? The molar mass of baking soda is 84.007 g/mol and the molar mass of carbon dioxide is 44.01 g/mol.

Mass of empty crucible (g) = 55.000

mass of crucible with baking soda (g) = 57.000

mass of crucible and contents after the reaction (g) =56.260

A. 2NaHCO3= 2Na+2CO2 +H2O

B. 2NaHCO3 = Na2O + 2CO2 +H2O

C. NaHCO3 = NaOH +CO2

D. 2NaHCO3 = Na2CO3 + CO2 +H2O

Balance the following Chemical Equations:

____Fe(s) + ____H₂O(g) Â® ____Fe₃O₄(s) + ____H₂(g)

____C₂H₆(g) + ____O₂(g) Â® ____CO₂(g) + ____H₂O(g)

___ C₆H₁₄ (l) + ___ O₂ (g) Â® ___ CO₂ (g) + ___ H₂O (g)

___ C₃H₈O₃ (l) + ___ O₂ (g) Â® ___ CO₂ (g) + ___ H₂O (l)

___ NaN₃ (s) Â® ___ Na (s) + ___ N₂ (g)

__ C₃H₅N₃O₉ Â® __ CO₂ + ___ N₂ + ___ H₂O + ___ O₂

Write and Balance the equations:

Aqueous calcium hydroxide reacts with aqueous sodium carbonate to produce solid calcium carbonate and aqueous sodium hydroxide.

Solid iron reacts with Oxygen gas to form solid Iron (II) oxide

Copper(II) sulfide is oxidized by molecular oxygen to produce gaseous sulfur trioxide and solid copper(II) oxide. The gaseous product then reacts with liquid water to produce liquid hydrogen sulfate as the only product. Write the two equations which represent these reactions.

Indicate what type, or types, of reaction each of the following represents: (precipitation, acid-base, and oxidation-reduction.)

(A) H₂O(g) + C(s) â¶ CO(g) +H₂(g)

(B) 2KClO₃(s) â¶ 2KCl(s) +3O₂(g)

(D) Pb(NO₃)₂(aq) + H₂SO₄(aq) â¶ PbSO₄(s) + 2HNO₃(aq)

4. Silver can be separated from gold because silver dissolves in nitric acid while gold does not. Is the dissolution of silver in nitric acid an acid-base reaction or an oxidation-reduction reaction? Explain your answer.

5. Determine the oxidation states of the elements in the compounds listed. None of the oxygen-containing compounds are peroxides or superoxides.

(A) H₃PO₄

(B) Al(OH)₃

6. Complete and balance the following acid-base equations:

(A) A solution of HClO₄ is added to a solution of LiOH.

(B) Aqueous H₂SO₄ reacts with NaOH.

7. Write the molecular, total ionic, and net ionic equations for the following reactions:

(A) Ca(OH)₂(aq) + HC₂H₃O₂(aq) â¶

(B) H₃PO₄(aq) + CaCl₂(aq) â¶

8. Write the balanced equation, then calculate the number of moles and the mass of Mg required to react with 5.00 g of HCl and produce MgCl₂ and H₂. Ans: 1.67 g Mg

9. H₂ is produced by the reaction of 118.5 mL of a 0.8775-M solution of H₃PO₄ according to the following equation: 2Cr + 2H₃PO₄ â¶ 3H₂ + 2CrPO₄. How many grams of H₂ are produced? Ans: .315 g H₂

10. Automotive air bags inflate when a sample of sodium azide, NaN₃, is very rapidly decomposed.

2NaN₃(s) â¶ 2Na(s) + 3N₂(g)

What mass of sodium azide is required to produce 2.6 ft³ (73.6 L) of nitrogen gas with a density of 1.25 g/L?

Ans: 142 g NaN₃

11. Urea, CO(NH₂)₂, is manufactured on a large scale for use in producing urea-formaldehyde plastics and as a fertilizer. What is the maximum mass of urea that can be manufactured from the CO₂ produced by combustion of 1.00 x 10⁴ grams of CO₂?

CO₂(g) + 2NH₃(g) â¶ CO(NH₂)₂(s) + H₂O(l)

Ans: 1360 g urea

12. What volume o f 0.750 M hydrochloric acid solution can be prepared from the HCl produced by the reaction of 25.0 g of NaCl with excess sulfuric acid? NaCl(s) + H₂SO₄(l) â¶ HCl(g) + NaHSO₄(s)

Ans: .570 L

13. A sample of 0.53 g of carbon dioxide was obtained by heating 1.31 g of calcium carbonate. What is the percent yield for this reaction? CaCO₃(s)â¶CaO(s) + CO₂(s)

Ans: 92.0 %

14. Citric acid, C₆H₈O₇, a component of jams, jellies, and fruity soft drinks, is prepared industrially via fermentation of sucrose by the mold Aspergillus niger. The equation representing this reaction is

C₁₂H₂₂O₁₁ + H₂O +3O₂ â¶2C₆H₈O ₇+ 4H₂O

What mass of citric acid is produced from the reaction of 150. grams of sucrose if the yield is 92.30%?

Ans: 155 g

15. The phosphorus pentoxide used to produce phosphoric acid for cola soft drinks is prepared by burning phosphorus in oxygen.

(A) What is the limiting reactant when 0.200 mol of P₄ and 0.200 mol of O₂ react according to P₄+5O₂ â¶ P₄O₁₀?

(B) Calculate the percent yield if 10.0 g of P₄O₁₀ is isolated from the reaction.

Ans: 88.0 %

16. What is the limiting reactant when 1.50 g of lithium and 1.50 g of nitrogen combine to form lithium nitride, a component of advanced batteries, according to the following unbalanced equation? Li + N₂ â¶ Li₃N

Ans: Li

17. What is the concentration of NaCl in a solution if titration of 15.00 mL of the solution with 0.2503 M AgNO₃ requires 20.22 mL of the AgNO₃ solution to reach the end point?

AgNO₃(aq) + NaCl(aq) â¶ AgCl(s) +NaNO (aq)

Ans: .3374 M

18. In a common medical laboratory determination of the concentration of free chloride ion in blood serum, a serum sample is titrated with a Hg(NO₃)₂ solution.

2Cl^â(aq) + Hg(NO₃)₂(aq) â¶ 2NO₃^â(aq) + HgCl₂(s)

What is the Cl^â concentration in a 0.25-mL sample of normal serum that requires 1.46 mL of .000825 M Hg(NO₃)₂(aq) to reach the end point?

Ans: 0.009636 M

CHEM 10 Lecture Notes - Lecture 7: Sodium Bromide, Sodium Hydroxide, Potassium Iodide

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