Organic Chemistry Review
Objective #43 What is the molecular formula of 2,3 dimethylbutane? What is its structural formula? What is the difference between a molecule’s structural formula and its molecular formula?
Answer C6H14 The structural formula shows what the molecule looks like; The molecular formula shows what its made of.
Objective #44 Draw 2 structural isomers of C8H18. What is a structural isomer?
Answer These have the same formula, but have different structures.
Objective #45 What is the difference between these 3 molecules: Hexane, hexene and hexyne?
Answer Hexane has only single bonds and is C6H14 Hexene has a double bond and is C6H12 Hexyne has a triple bond and is C6H10
Objective #46 Draw the structural formula for the following molecules: 3, ethyldecane 2, hexyne 3, octene
Answer
Objective #46 Name these molecules
Answer 3, ethylpentane 1, butene 3, ethylhexane
Objective #47 What is the difference between a saturated hydrocarbon and an unsaturated hydrocarbon?
Answer Every carbon in the saturated hydrocarbon has the maximum number of hydrogens possible. Every carbon in the unsaturated carbon does not. Saturated hydrocarbons only have single bonds; unsaturated hydrocarbons have double or triple bonds.
Objective #48 Identify each of these as an alcohol, ester or carboxylic acid:
Answers Alcohol Ester Carboxylic acid
Objective #49 Show the ester that is produced when the alcohol and carboxylic acid shown react with one another:
Answer
Objective #50 Write the balanced chemical equation for the combustion of pentane.
Answer C5H12 + 8 O2 5 CO2 + 6 H2O
Objective #51 You are heating 90 grams of water with a candle. The temperature of the water increases from 10oC to 45oC. How much thermal energy was produced by the candle?
Answer Mass of water x Temperature change x Specific heat 90 grams x 35oC x 4.2 joules/gram oC = 13,230 joules or 13.2 kilojoules or 13.2 kJ
Objective #52 During the last experiment, you used 0.4 grams of the candle. What is the heat of combustion of candle wax?
Answer Thermal energy / mass of fuel used =heat of combustion 13.2 kJ / 0.4 grams = 33.0 kJ / gram
Objective #53 What is the specific heat of water?
Answer 4.2 joules/gram oC or 1.0 calories/gram oC Specific heat is the energy required to raise the temperature of 1.0 gram of water 1.0 degree Celsius
Objective #53 How many joules are there in 100 Calories?
Answer 100 Calories = 100,000 calories 1 calorie = 4.2 joules 100,000 calories x 4.2 joules / 1 calorie = 420,000 joules
Objective #54 Define Calorie You want to increase the temperature of 100 grams of water from 15oC to 100oC. How many Calories do you need?
Answer The amount of heat energy required to raise the temperature of 1 liter of water 1 degree Celsius. 100 grams x 85oC x 1 calorie /goC = 8500 calories 8500 calories = 8.5 Calories