I need help with the questions please THE COMBINED GAS LAW& THE IDEAL GAS EQUATI
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I need help with the questions please
THE COMBINED GAS LAW& THE IDEAL GAS EQUATION When magnesium solid is reacted with hydrochloric acid, hydrogen gas is produced. Mg + 2HCl MgCl2 . I12 Eqn. 1 The balanced reaction equation shows that the molar ratio of magnesium reacted to hydrogen produced is 1:1. Thus, by knowing either the amount of magnesium consumed, or the amount of hydrogen gas produced, you are able to determine the other The primary objective of the first part of this experiment is to confirm that the molar volume of hydrogen gas at STP is indeed 22.4 Lmol using the combined gas lavw P1VI Eqn. 2 Avogadro's hypothesis states that equal volumes o gases contain equal numbers of molecules under the same conditions of temperature and pressure. The standard temperature and pressure (also known as STP) for Avogadro's hypothesis is 0°C (273 K) and 1 atm (101.3 kPa). The commonly accepted value that puts a finishing touch on this hypothesis is: 22.4 Lmol, which is to say that if you have exactly one mole of any gas, at 273 K and 101.3 kPa pressure that gas will occupy 22.4 L of space. This volume is called the molar volume You will react a known mass of solid magnesium with an excess of hydrochloric acid. The reaction will be conducted in a sealed vessel, thus trapping the H2(g) in the vessel. Yo Gas Pressure Sensor to measure the pressure incre probe to measure the temperature of the reaction indirectly, by measuring the temperature of the water bath in which the vessel will be placed. You will also calculate the number of moles of hydrogen indirectly. To confirm Avogadro's hypothesis, you will use the Combined Gas Law to u will use a Iculate the volume, at STP, of the hydrogen gas your reaction produced at nonstandarcd conditions The primary objective of the second part of this experiment is to use the volume of hydrogen gas liberated to calculate the mass of magnesium metal which reacted with excess hydrochloric acid according to Eqn 1. Percent error will then be calculated based on the actual mass used ©Vernier Software & Technology Page 1Explanation / Answer
Answer 1:
I learned a new technique to safely conduct a reaction between a metal and HCl and to measure the pressure and volume of gas liberated by this reaction.
Answer 2: In part 1 we are not in direct contact with the HCl and hence we can use a solution of HCl in water. But in part 2, during the set-up of reaction, we are inserting the buratte to the beaker in inverted position. In this case there is a chance of skin contact with HCl. Hence it is better to add first concentrated (12N) HCl and ther water with minimum mixing. By doing this it will be safe to transfer the buratte to the beaker in inverted position (there will not be skin contact with HCl). Moreover, afterward by mixing the water and HCl in the buratte the strength of the HCl will be same as in part 1 (12 N * 4 mL = XN * ~50 mL): then X = ~1 N (as in part 1).
Answer 3: In part 1 there is no any contact with the water and the system (reactoin system of the Erlenmeyer flask), the pressure of the system is analyzed by the pressure guage connected to the system directly. So we do not need to equalize the pressure in part 1.
But in part 2, when we are submerging the buratte (or the reaction system) to the beaker, as soon as when we are taking our finger from the opening of the rubber stopper, the reaction system will be in contact with the water in the cylinder. Hence the pressure exterted by the atmosphere on the water in the cylinder will influence the pressure of the reaction system. Hence we have to equalize both the pressure to get the accurate reading.
Answer 4 A: If the student neglect to take the vapour pressure of water during the reaciton, then he/she will get little higher value in the mass of Mg than the actual value. Beacue, the total pressure is the sum of partial pressure of H2 and H2O. So if the student neglect to take the vapour total pressure will be higher than the actual and hence the mass of Mg will be higher than the actual.
Answer 4 B: If the student poured the water to HCl without caution and if HCl is get diluted, there will not be any change in the calculated mass of Mg but there will be a risk of skin contact of HCl.
Answer 4 A: If you wrongly recorded the temperature of thermometer as 45 oC, instead of 24.6 oC, then there you will get a wrong molar volume. It will be a reduced value of 22.96/1.07 = 21.46. (1.07 is the fraction that [(1/297.6 K)/1/318 K).
Answer 4 B: Same as in previous part, you will get a wrong mass of Mg with a factor of 1.07. But here the value will be more than that of actual value. (Please refer the 2nd equation).