Download presentation

Presentation is loading. Please wait.

Published byThaddeus Tredway Modified over 2 years ago

1
Experiment 7 The Gas Constant

2
Purpose and Goals To determine the gas constant R, by collecting H 2 produced when a known amount of Mg reacts with acid.

3
Principles According to the ideal gas law, PV=n RT(1) Rearrange the equation, R=PV/ n T(2) if P,V, n,T are known, we can calculate R by equation (2).

4
In this experiment P : pressure of H 2, P H2 =P bar - P H2O V: volume of H 2 collected n: moles of H 2 T: absolute temperature (K)

5
Prepare the solutions: Solution 1: 50 ml H 2 O + 10ml 6M HCl ( used for reaction) Solution 2: 90 ml H 2 O + 10 ml solution1 (used for cleaning of Mg ribbon) Procedure

6
Procedure (cont.) Submerse a 100 ml cylinder and a 1000 ml beaker in the sink. Make sure that there are no bubbles in the top of the cylinder. Keep the cylinder inverted when they are removed from the water

7
Procedure (cont.) Put the rubber hose inside the cylinder.

8
Procedure(cont.) Clean the Mg ribbon with solution 2 Take the metal out, rinse and dry it Weigh out about 0.070g~0.075g of Mg, record the mass

9
Procedure(cont.) Place 12 ml solution 1 into the test tube, then the weighed Mg ribbon When all the Mg disappears, record the volume in ml. After you finish experiment, record the barometric pressure and room temperature Do not let Mg react with acid. tilt the test tube at an angle, put in the metal,insert the rubber stopper, then turn the test tube upright

10
Reminders Water level inside and outside cylinder are even. Always wear the safety goggles

11
R=PV/nT (1) P H2 (torr) =P bar - P H2O P bar : given on board in torr P H2O : given on page7- 4 in torr. P H2( atm)=P torr / 760 (torr/atm) (2) V H2 (L), change milliliter to liter dividing by 1000 ml/L Calculations

12
Calculations(Con.) (3) n moles of H 2 Mg + 2HCl MgCl 2 + H 2 1 mass/24 n (4) T absolute temperature T (K) = t ° (centigrade) + 273 The unit of R is atm.L/ mole.K

13
(5)Average value of R = (R1 + R2 + R3)/3 % Error = (average R - 0.0821)x100% 0.0821 Accepted R is 0.0821 atm. L/mole.K Calculations(Con.)

Similar presentations

OK

Laboratory 1 - Calculating the Ideal Gas Constant Purpose: To use a sample of butane gas, C 4 H 10, to experimentally determine the value of the universal.

Laboratory 1 - Calculating the Ideal Gas Constant Purpose: To use a sample of butane gas, C 4 H 10, to experimentally determine the value of the universal.

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on polynomials in maths what does product Hypothalamus anatomy and physiology ppt on cells Ppt on immunisation schedule Ppt on ganga action plan download Ppt on satellite orbital locations Ppt on area of parallelogram and triangle Animated ppt on magnetism perfume Ppt on electricity for class 10th exercise Ppt on congruence of triangles class 8 Ppt on 4 types of sentences