1st Semester - Organic Chemistry Practical Midterm Examination 2023-2024
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Questions and Answers

What is the purpose of a burette in a laboratory setting?

  • Measuring the boiling point
  • Mixing solute with solvent
  • Measuring the melting point
  • Measuring the volume of liquid (correct)

Influencing factors on the boiling point include ____________, ____________, and ____________.

  • Atmospheric pressure, material composition, temperature (correct)
  • Stirring speed, time, humidity
  • Volume, color, weight
  • Glassware, temperature, pressure

Why is it important to determine the melting point of organic compounds?

  • To influence the boiling point
  • To measure the solubility
  • To calculate the volume of liquid
  • To identify the compound (correct)

What type of glassware is used for transferring solid material from a reagent bottle?

<p>Spatula (B)</p> Signup and view all the answers

Which piece of glassware has one calibration mark and is used to deliver fixed volumes of liquid?

<p>Pipette (B)</p> Signup and view all the answers

What is the main purpose of studying simple distillation in the organic chemistry lab?

<p>To purify a compound by separating it from a non-volatile or less-volatile material. (C)</p> Signup and view all the answers

In simple distillation, what does the boiling point of a liquid determine?

<p>The volatilities of the components in the mixture. (A)</p> Signup and view all the answers

What does miscible mean in the context of simple distillation?

<p>Able to mix in all proportions. (A)</p> Signup and view all the answers

Why is it important to record the initial temperature of the solution in a simple distillation experiment?

<p>To set a reference point for monitoring temperature changes. (B)</p> Signup and view all the answers

What is the significance of using a condenser in simple distillation?

<p>To prevent loss of volatile components by cooling and condensing them back into liquid form. (A)</p> Signup and view all the answers

What does the final volume of the distilled solution represent in a simple distillation experiment?

<p>The yield or quantity of purified compound obtained from the process. (B)</p> Signup and view all the answers

Why is the boiling temperature reduced under normal (atmospheric) pressure?

<p>Organic fluids disintegrate before reaching the boiling point (D)</p> Signup and view all the answers

How does external pressure affect the boiling temperature according to the text?

<p>It reduces the degree of boiling by boiled external and controlled pressure (B)</p> Signup and view all the answers

What type of impurities affect the boiling point of a compound according to the text?

<p>Organic compounds and low temperature (A)</p> Signup and view all the answers

How does feeding water from the bottom in a condenser affect condensation?

<p>It helps in achieving high cooling due to slow speed (B)</p> Signup and view all the answers

What happens to the condenser speed when water is fed from the top according to the text?

<p>Speed increases leading to better cooling (C)</p> Signup and view all the answers

How does steam pressure correlate with temperature according to the text?

<p>Steam pressure increases proportionally with temperature (C)</p> Signup and view all the answers

Flashcards

What is a burette?

A laboratory instrument used to measure the precise volume of liquid dispensed, typically in a titration experiment.

What factors influence boiling point?

Atmospheric pressure, material composition, and temperature all influence the boiling point of a substance.

Why is melting point important?

Determining the melting point of an organic compound helps identify the compound due to its unique melting point.

What is a spatula used for?

A spatula is a laboratory utensil used to transfer solid materials from a reagent bottle to another container.

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What is a pipette?

A pipette is a laboratory tool used to transfer a specific, fixed volume of liquid, often marked with a single calibration line.

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What is the purpose of simple distillation?

Simple distillation is used to purify a compound by separating it from impurities that are less volatile or non-volatile.

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What does boiling point determine in distillation?

In simple distillation, the boiling point of a liquid determines the relative volatilities of the components within a mixture. More volatile components vaporize first.

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What does 'miscible' mean?

Miscible refers to substances that can mix in any proportion, forming a homogeneous solution.

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Why record the initial temperature?

Recording the initial temperature of the solution in a simple distillation experiment provides a reference point to monitor temperature changes throughout the process.

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What is the purpose of a condenser?

A condenser in simple distillation cools and condenses vapors back into liquid form, preventing loss of volatile components.

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What does the final volume represent?

The final volume of the distilled solution represents the yield of the purified compound obtained after the distillation process.

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Why does boiling temperature decrease with lower pressure?

Under normal atmospheric pressure, the boiling point of a liquid is lowered because the external pressure decreases. This is why liquids boil at lower temperatures at higher altitudes.

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How does pressure affect boiling temperature?

External pressure directly affects the boiling temperature of a liquid. Increased external pressure leads to a higher boiling point, while decreased pressure lowers the boiling point.

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How do impurities affect boiling point?

Impurities affect the boiling point of a compound by altering its volatility. Organic compounds and low-temperature impurities tend to lower the boiling point.

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How does water flow affect condenser cooling?

Feeding water from the bottom of a condenser promotes better cooling by creating a counter-current flow, allowing colder water to meet the hottest vapors.

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How does water flow from the top affect condenser cooling?

When water is fed from the top of a condenser, the speed of water flow increases, leading to faster but less effective cooling.

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How are steam pressure and temperature related?

Steam pressure increases proportionally with temperature. As temperature rises, more water molecules gain enough energy to escape as steam, leading to higher pressure.

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