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Scarlett McBride
5 years ago
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1 Expansion of Gases. It is decided to verify oyle's law over a wide range of teperature and pressures. he ost suitable gas to be selected for this purpose is ) Carbon dioxide ) Heliu 3) Oxygen 4) Hydrogen. When the volue of a saturated vapour is decreased, its pressure ) Increases according to oyle's law ) Decreases according to oyle's law 3) Changes but not according to oyle's law 4) Reains constant 3. Under which of the following conditions VR is obeyed ost closely by a real gas? ) High pressure and high teperature ) Low pressure and low teperature 3) Low pressure and high teperature 4) High pressure and low teperature 4. Equation of gas in ters of pressure (p), absolute teperature () and density (d) is d ) d d d d ) 3) 4) d d d 5. saple of an ideal gas occupies a volue 'V' at pressure '' and absolute teperature ''. he ass of each olecule is. he expression for the density of gas is ) K ) /K 3) /KV 4) /K 6. he ratio of the volue expansivity of Heliu to pressure expansivity of Hydrogen is ) ) 3) 73 4) 7. he difference between volue and pressure coefficient of an ideal gas is ) /73 ) 73 3) /73 4) Zero 73

2 8. he graph between teperature in ºC and pressure of a perfect gas is ) Hyperbola ) straight line passing though the origin 3) straight line parallel to pressure axis intercepting teperature axis as -73 C 4) straight line with +ve intercept on pressure axis and intercepting the teperature axis as -73 C 9. real gas can be approxiated to an ideal gas at ) Low density ) High pressure 3) High density 4) Low teperature. he increase in volue of the bubble as it rises fro the botto of the beaker with water at constant teperature is due to ) Charles s law ) oyle's law 3) vogadro's law 4) Dalton's law. Match the following. LIS - I LIS - II a) - V graph ( is constant) e) St Line cutting ep. axis at 73 C b) - graph (V is constant) f) Rectangular Hyperbola c) V - t graph ( is constant) g) St Line parallel to pressure axis d) V - graph ( is constant) h) St Line passing through origin ) a - g, b - e, c - h, d - f ) a - h, b - f, c - g, d - e 3) a - e, b - g, c - f, d - h 4) a - f, b - h, c - e, d - g. If a given ass of a gas occupies a volue cc at one atospheric pressure and a teperature of C. What will be its volue at 4 atospheric pressure the teperature being the sae? ) c 3 ) 4 c 3 3) 5 c 3 4) c 3

3 3. gas at 7 C and pressure of 3 at is allowed to expand to atosphere pressure and volue 5 ties larger. he final teperature of the gas is... ) 3 C ) 3 C 3) 3 C 4) 3 C 4. If the pressure of an ideal gas contains in a closed vessel is increased by.5%, the increase in teperature is C. he initial teperature of the gas is ) 7 C ) 7 C 3) 3 C 4) 4 C 5. t constant pressure, the ratio of increase in volue of an ideal gas per degree rise in Kelvin teperature to its original volue is ) 3 ) 73 3) 6. For an ideal gas V- curves as constant pressures & are shown in figure - fro the figure 73 ) > ) < 3) 4) 7. wo different curves at const teperature. he relationship between volue V and the pressure at a given tep of sae ideal gas are shown for asses and of the gas respectively. hen V ) > ) 3) < 4) 4) 3

4 8. gas at a teperature 3 K and pressure 3 at is allowed to expand to atospheric pressure. If the volue becoes ties its initial volue, the final teperature becoes ) C ) 373K 3) 373 C 4) K 9. o decrease the pressure of the gas by % at constant teperature then change in volue should be ) % decrease ) % increase 3).% increase 4) 9.% increase. gas is heated through C in a closed vessel. Its pressure is increased by.4%. he initial teperature of the gas is ) 5 C ) C 3) 75 C 4) 3 C. he variation of pressure with volue for a given ass of a gas at two different teperatures and are represented as shown in the graph, then ) > ) > 3) 4). Fro the following diagra, the inference drawn is V θ θ V > < ) V > V ) V < V 3) V V 4) None of hese

5 3. When an air bubble of radius 'r' rises fro the botto to the surface of a lake, its radius becoes 5r/4 (the pressure of the atosphere is equal to the height of water colun). If the teperature is constant and the surface tension is neglected, the depth of the lake is ) 3.53 ) ) ) n ideal gas is trapped between ercury thread of c and the closed lower end of a narrow vertical tube of unifor cross section. Length of the air colun is.5 c, when the open end is kept upward. If the tube is aking 3º with the horizontal then the length of the air colun is (assuing teperature to be constant and atospheric pressure 76c of Hg) ) c ) 8 c 3) 4 c 4). c 5. wo therally insulated vessels and are filled with air at teperature (, ), volue (V, V ) and pressure (, ) respectively. If the valve joining the two vessels is opened, the teperature inside the vessel at equilibriu will be ) + ) ( V + V ) / ( V + V ) 3) ( V + V ) / ( V + V ) 4) ( + ) / 6. During an experient an ideal gas is found to obey an additional law V constant. he gas is initially at a teperature '' and volue 'V'. When it expands to a volue V, the teperature becoes ) ) 3) 4) 7. One liter of oxygen at a pressure of at and two liters of nitrogen at a pressure of.5 at are introduced into a vessel of volue litre. If there is no change in teperature, the final pressure of the gas in at is ).5 ).5 3) 4) 4

6 8. wo identical vessels and with frictionless pistons contain the sae ideal gas at the sae teperature and the sae volue V. he asses of gas in and are respectively. he gases are allowed to expand isotherally to the sae final volue 3 V. he change in pressures of the gas in and are found to be and.5 respectively. hen ) 9 4 ) 3 3) 3 4) horizontal unifor glass tube of c length sealed at both ends contains c ercury colun in the iddle. he teperature and pressure of air on either side of ercury colun are respectively C and 8c of ercury. If the air colun at one end is kept at C and the other end at 73 C, the pressure of air which is C is (in c of Hg) ) 76 ) 88. 3) 4) 3 3. saple of an ideal gas occupies a volue V at a pressure and absolute teperature. he ass of each olecule is. If K is the oltzann constant, then the density of the gas is K ) d ) d S 3) d 4) d K K Key ) 4 ) 3 3) 3 4) 5) 4 6) 7) 4 8) 4 9) ) ) 4 ) 3 3) 4) 5) 3 6) 7) 8) 4 9) 3 ) 4 ) ) 3) 3 4) 5) 3 6) 7) 3 8) 9) 3 3)

7 Hints. p V p V V p v p 4 p V 3. 5cc p V 3 V 5V 3 5 K -3 C 4. % Change in pressure Vt V 5. V t 4k 7 C 6. V const α ( ) 73 C (slope) const (tan θ ) const tanθ θ < θ < > 7. V const V const [ isconst ] If we consider V const in fig, then p

8 is ore for upper curve > V V 8. 3V x V 3 K 9. % change in vol n + n.% Volue increase by.% K 3 C V V. Here > < < ( or) >. V const ( ) V slope const V < V V α slope

9 3. V V ( H + h) r 3 Hr 3 5 x 64 ( + h) r 3 r 3 5 h l l ( + ) ( + sinθ ) H x l H x l ( 76 + ).5 ( H + x sinθ ) l ( 78 + ) x l 88 x.5 8l 88 x.5 l 8 c V V V V V + V V + V ( + ) V V V + V 6. V R and V const V V V V 7. V + V V x +.5 x x

10 8. at V R M V,, const α Or α 3 3 l l 9. i) ( 45 x) Or 8x ii) ( 45 + x) ' 8x Fro () and () ( 45 ) ( 45 + ) x x x 45 + x 3x 45 or x 5c ' c of Hg 3. V nr d nr otal ass n N.5 R nn nr d K d K N

Chemistry Department Al-kharj, October Prince Sattam Bin Abdulaziz University First semester (1437/1438)

Chemistry Department Al-kharj, October Prince Sattam Bin Abdulaziz University First semester (1437/1438) Exercise 1 Exercises- chapter-1- Properties of gases (Part-2- Real gases Express the van der Waals paraeters a = 1.32 at d 6 ol 2 and b = 0.0436 d 3 ol 1 in SI base units? * The SI unit of pressure is