Halloween CHEM 1500

Combustion Catastrophe

100

General formula for a combustion reaction

C_xH_yO_z + O2 --> H2O + CO2

200

When a 10.0 g sample of an unknown organic acid is subjected to combustion analysis 21.2 grams of CO2 and 3.25 g of H2O are produced. What is the empirical formula of this sample?

C₄H₃O₂

_{source: https://www.mychemistryclass.net/Files/HONORS%20CHEM/8%20Advanced%20Chemical%20Ratios/Packet/Advanced%20Chemical%20Ratios%20WS%2012%20Extra%20Practice%20Combustion%20Analysis.pdf}

300

A 0.1034 g sample of an unknown compound is subjected to combustion analysis, producing 0.2351g CO2 and 0.0962 g H2O. What is the empirical formula for the compound?

C₃H₆O

source:https://www.mychemistryclass.net/Files/HONORS%20CHEM/8%20Advanced%20Chemical%20Ratios/Packet/Advanced%20Chemical%20Ratios%20WS%2012%20Extra%20Practice%20Combustion%20Analysis.pdf

400

12.915 g of a biochemical substance containing only carbon, hydrogen, and oxygen was burned in an atmosphere of excess oxygen. Subsequent analysis of the gaseous result yielded 18.942 g carbon dioxide and 7.749 g of water. Determine the empirical formula of the substance. 

CH2O

source: https://www.chem.fsu.edu/chemlab/chm1045/Combustion%20Analysis%20Extra%20Problems%20Key.pdf

500

33.658 g of oxygen was used to completely react with a sample of a hydrocarbon in a combustion reaction. The reaction products were 33.057 g of carbon dioxide and 10.816 g of water. Find the empirical formula

C5H8

source: https://www.chem.fsu.edu/chemlab/chm1045/Combustion%20Analysis%20Extra%20Problems%20Key.pdf

Empirical Evidence and Molecular Mysteries

100

What is the difference between a molecular and empirical formula?

Empirical: most reduced

Molecular: how the molecule appears in real life

200

What is the empirical formula: 15.8% carbon and 84.2% sulfur

CS₂

300

Find the empirical formula of a molecule that is 6.54 grams of carbon and 13.1 grams of hydrogen, and 13.4 grams of oxygen.

C₂H₄₈O₃

400

Determine the empirical and molecular formula for chrysotile asbestos. Chrysotile has the following percent composition: 28.03% Mg, 21.60% Si, 1.16% H, and 49.21% O. The molar mass for chrysotile is 520.8 g/mol.

source: ChemLibre texts

Mg₃Si₂H₃O₈ 

 Mg₆Si₄H₆O₁₆

500

A molecule has a percent composition of 75.95% C, 17.72% N, and 6.33% H by mass with a molar mass of about 240 g/mol. What is the molecular formula?

source: Chem Libre text

C₁₅H₁₅N₃

Balancing Equations

100

__NaBr + __Cl2 --> __NaCl  + __Br2

2NaBr + Cl2 --> 2NaCl + Br2

200

Balance this equation: 

__Fe + __H2SO4 --> __Fe2(SO4)3 + __H2

2Fe + 3H2SO4 --> Fe2(SO4)3 + 3H2

300

What is a limiting reactant?

Part that limits the total amount of substance formed

400

__NH3 + __O2 --> __NO + __H2O

4NH3 + 5O2 --> 4NO + 6H2O

500

(NH4)3PO4 + Pb(NO3)4 --> Pb3(PO4)4 + NH4NO3

4(NH4)3PO4 + 3Pb(NO3)4 --> Pb3(PO4)4 + 12NH4NO3

Trick or Treat

100

How many atoms of silver are in 36.5 kg of silver nitrate?

1.29 x10²⁶ 

200

If witches are making a potion and they use 3.25 oz of bile in the potion, what is this in kg?

0.0921

300

A werewolf is chasing you. If you are running at 12 mph and the werewolf is running at 7.5 m/s, can the werewolf catch you?

Yes

16.78 mph is how the fast the wereworf is running

400

What food are vampires allergic to?

Garlic

500

Who wrote Dracula?

Bram Stoker

Halloween Trivia

100

What holiday is Halloween based off of?

Samhain

200

What is the largest bat?

Golden-capped fruit bat

300

What are the Hocus Pocus Sanderson sisters names?

Winifred, Mary, and Sarah

400

What do you call a group of witches?

A coven

500

On average, how many seeds are there in a pumpkin?

500