Unit 3: Gases, Liquids, Solids, Solutions and Electrochemistry 3. 10 Unit 3: Gases, Liquids, Solids, Solutions and Electrochemistry 3.10.6 Manometers Textbook 10.3

Learning Objectives: SWBAT: Big Idea 2: Chemical and physical properties of materials can be explained by the structure and the arrangement of atoms, ions, or molecules and the forces between them. Students will be able to demonstrate understanding by laboratory investigation, analysis of data and creation of models. Learning Objectives: SWBAT: Calculate the total pressure of a gas mixture given its partial pressure

How to read a manometer A manometer is a simple U-tube filled with mercury. One end would have a sample of a gas and the other end would be open to the atmosphere or possible closed.

In this system pressure of gas is equal to: 1. Closed End Manometers: As you can see from the picture given below one end of manometer is open to gas container and one of them is closed. x and y points in the picture are at same level, thus pressures acting on these points are equal. Pressure at point x is the pressure of gas and pressure at point y is the pressure of mercury at h height.   In this system pressure of gas is equal to: Pgas=h

2. Open manometer system Pgas = Patm - ha Pgas = Patm + hb Pressure from gas great than atmosphere and pushed Hg

(A) 28 mm Hg (B) 56 mm Hg (C) 133 mm Hg (D) 161 mm Hg (E) 189 mm Hg The system shown above is at equilibrium at 28 °C. At this temperature, the vapor pressure of water is 28 millimeters of mercury. The partial pressure of O2(g) in the system is (A) 28 mm Hg (B) 56 mm Hg (C) 133 mm Hg (D) 161 mm Hg (E) 189 mm Hg Use Daltons law partial pressure: Pt = Pwater vapor + Poxygen

References Our textbook: Brown, Lemay et all. AP edition chemistry, 13th edition, 2015