CHEMENG 2D04 Lecture Notes - Lecture 1: Boiling Point, Chemical Property, Physical Property

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10 Sep 2016

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Chapter 1: matter, measurement & problem solving 1) the scienti c approach (p. 14) Hypothesis, scienti c law & theory: classi cation of matter (p. 45) Solids: can be either crystalline or amorphous (eg: diamond and charcoal) liquids: molecules are closely packed but have some ability to move around gases: atoms have complete freedom from each other. Homogeneous eg: nitrogen & oxygen (can be mixed and will still be homogeneous) heterogeneous eg: wet sand. Composition: parts or components of a sample of matter and their relative proportions. Physical property: characteristics a substance displays without changing its composition (eg volatility [boiling point]) Chemical property: characteristics a substance displays only when changing its composition (eg ammability) Work: actions of a force applied across a distance. Electrostatic force: push or pull on objects that have an electrical charge. Potential energy: energy that is stored in matter can be introverted.

Related Questions

Question 11 pts

Which general statement about gases is NOT correct?

The molecules of a pure gas are distributed evenly throughout the container.

Gases are much less dense than liquids or solids

Molecules in a gas mixture can form layers according to their densities

Gases can be compressed, even to the point of liquefaction

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Question 21 pts

Which example is the greatest pressure?

1.00 atm

101 kPa

760 mm Hg (= 760 torr)

All of the above pressures are equal.

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Question 31 pts

Which example is the greatest pressure?

850 mm Hg (= 850 torr)

1.5 atm

All of the above pressures are equal.

96 kPa

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Question 41 pts

Assuming all other variables are held constant, a graph of which of the following will NOT yield a straight line?

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Question 51 pts

A sealed vessel contains 0.250 mol of oxygen gas. Which of the following will result in a decrease in the pressure of the oxygen gas?

increasing the number of moles of oxygen

increasing the temperature of the vessel

increasing the volume of the vessel

adding some helium to the vessel

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Question 61 pts

According to Charlesâs law, which change will cause the pressure of a gas to double? Pressure and amount of gas are constant.

The temperature decreases from 650 K to 325 K.

The temperature of the sample decreases fromï¿½88 Â°C to 44 Â°C.

The temperature of the sample increases fromï¿½22 Â°C to 44 Â°C.

The temperature of the sample increases fromï¿½250 K to 500 K.

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Question 71 pts

Which set of units for P, V, and T can be used for combined gas law calculations?

torr, L, and Kelvins

tm, g/L, and Kelvins

atm, mL, and degrees Celsius

inches of mercury, g/mL, and degrees Celsius

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Question 81 pts

The vapor pressure of a gas is

the atmospheric pressure at which the boiling point is determined.

the pressure at a Kelvin temperature exactly two times the boiling point.

impossible to determine experimentally without knowing the temperature and volume.

the pressure above a gas sample when evaporation and condensation are balanced.

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Question 91 pts

In a chemistry experiment where CO2 is collected over water, the atmospheric pressure is 755 mm. The partial pressure of water at the temperature in the lab is 24.2 mm. What is the pressure of the CO2?

779 mm

731 mm

More information is needed to answer this question

755 mm

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Question 101 pts

Which statement is NOT true according to the kinetic molecular theory of gases?

Molecules undergo elastic collisions

Molecules move in straight-line paths.

Molecules of different gases have differentï¿½kinetic energies at the same temperature

Molecules occupy a negligible volume.

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