There Is Concern That the Combustion of Fossil Fuels Such

question 9

Multiple Choice

There is concern that the combustion of fossil fuels such as coal and petroleum contributes to climate change by adding carbon dioxide to the atmosphere. Electric cars are being promoted as a way to address this situation by reducing the use of gasoline. Yet most electricity is produced by coal-fired power plants. Several factors need to be considered in determining whether electric cars actually are helpful in this regard. One is the environmental value of these fuels. Estimate the environmental value of coal compared to gasoline from the following information. The environmental value is defined as the amount of energy obtained per mole of carbon dioxide produced, so a larger environmental value is better. $$\begin{array} { c c c c } \text { Substance } & \text { Model Compound } & \text { Molar } \text { Mass } & \boldsymbol { \Delta } \boldsymbol { H } ^ { \circ } \text { combution } \\\text { coal } & \mathrm { C } _ { 135 } \mathrm { H } _ { 96 } \mathrm { O } _ { 9 } \mathrm { NS } & 1,906 \mathrm {~g} / \mathrm { mol } & 44,000 \mathrm {~kJ} / \mathrm { mol } \\\text { gasoline } & \mathrm { C } _ { 8 } \mathrm { H } _ { 18 } & 114 \mathrm {~g} / \mathrm { mol } & 5,460 \mathrm {~kJ} / \mathrm { mol }\end{array}$$

• A) coal = 23.1 kJ/mol, gasoline = 47.9 kJ/mol is better
• B) coal = 386 kJ/mol is better, gasoline = 2.86 kJ/mol
• C) coal = 182 kJ/mol is better, gasoline = 152 kJ/mol
• D) coal = 326 kJ/mol, gasoline = 683 kJ/mol is better
• E) coal = 527 kJ/mol is better, gasoline = 224 kJ/mol

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Definitions:

Population Locations

General or specific areas where members of a defined population reside or are positioned.

Kruskal-Wallis Test

A non-parametric method used for comparing more than two samples that are independent, or not related.

Null Hypothesis

A statement that there is no difference or effect, typically to be tested against an alternative hypothesis proposing a difference or effect.

Significance Level

The probability of rejecting the null hypothesis when it is actually true; a threshold chosen by the researcher to indicate the level of evidence needed to reject the null hypothesis.