The Following Reaction Is Used to Generate Hydrogen Gas in the Laboratory

question 161

Multiple Choice

The following reaction is used to generate hydrogen gas in the laboratory. If 243 mL of gas is collected at 25 °C and has a total pressure of 0.9933 bar, what mass of hydrogen is produced? A possibly useful table of water vapour pressures is provided below. Mg(s) + 2HCl(aq) → MgCl₂(aq) + H₂(g) T (°C) P (bar)
20 0.023398
25 0.031704
30 0.042477

• A) 0.0196 g H₂
• B) 0.0717 g H₂
• C) 0.0190 g H₂
• D) 0.0144 g H₂
• E) 0.0449 g H₂

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Definitions:

Variance

A measure of the dispersion of a set of data points around their mean value, indicating how spread out the data are.

Tornado Chart

A visual representation used in sensitivity analysis to compare the relative importance of variables.

Decision Table

A tabular method for representing and analyzing logical relationships between conditions and actions, used in decision-making and systems analysis.

Decision Variable

A variable in optimization or decision-making models whose value is subject to choice within a set of permissible values.