What would be the effect on the calculated value of R of each of the following experimental errors?

Explain each answer.

a. the liquid level in the eudiometer tube is lower than that in the beaker, but this is not taken into consideration in the calculations.

b. the balance used to weight the magnesium gives a mss that is higher than actual

c. some H2 escapes into the beaker during the reaction.

a. If the liquid level in the eudiometer tube is lower than that in the beaker, and this is not taken into consideration, the volume of gas collected in the eudiometer tube will be lower than it should be. The calculated value of R, which is obtained using the collected gas volume, will be smaller than the actual value. This is because the gas volume is inversely proportional to the calculated value of R. If the gas volume is underestimated, the calculated R value will be overestimated.

b. If the balance used to weigh the magnesium gives a mass that is higher than the actual mass, the number of moles of magnesium will be overestimated. This will lead to an overestimation of moles of hydrogen gas too, since the reaction between magnesium and an acid produces hydrogen gas. Since the calculated R value is directly proportional to the number of moles of gas, an overestimate of moles of gas will result in an overestimate of the calculated R value.

c. If some H2 gas escapes into the beaker during the reaction, the amount of gas collected in the eudiometer tube will be lower than it should be. This will result in an underestimate of the gas volume. As mentioned in (a), if the gas volume is underestimated, the calculated R value will be overestimated. This is because the gas volume is inversely proportional to the calculated value of R.

a. The effect on the calculated value of R for this experimental error would be an underestimation or lower value of R. This is because the volume of the liquid in the eudiometer tube is not taken into consideration in the calculations. Since R is directly proportional to the volume of the gas, a lower volume would result in a lower calculated value of R.

To avoid this error and get an accurate value of R, it is important to make sure that the liquid level in the eudiometer tube is the same as or higher than the liquid level in the beaker. This can be achieved by adjusting the liquid levels or using a different apparatus with better accuracy and precision.

b. The effect on the calculated value of R for this experimental error would be an overestimation or higher value of R. This is because the balance used to measure the mass of the magnesium is giving a reading that is higher than the actual mass.

To obtain an accurate value of R, it is crucial to use a balance that is calibrated properly and provides precise measurements. In this case, if the balance consistently gives a higher mass reading, it is important to either recalibrate the balance or use a different balance altogether. Ensuring accurate measurements of reactants is essential for obtaining reliable results in the calculations.

c. The effect on the calculated value of R for this experimental error would also be an underestimation or lower value of R. This is because some of the H2 gas escapes into the beaker during the reaction.

To minimize the amount of H2 gas escaping, it is important to ensure a tight seal or connection between the reaction vessel and the eudiometer tube. This can be achieved by using appropriate stoppers, clamps, or sealing mechanisms. Minimizing gas loss is crucial to obtaining accurate results for R. If a significant amount of gas does escape despite precautions, additional corrections or considerations might be required in the calculations to account for the lost gas volume.

a. If the liquid level in the eudiometer tube is lower than that in the beaker and this discrepancy is not taken into consideration in the calculations, it would result in an overestimate of the calculated value of R (the ideal gas constant). This is because the volume of the gas collected would be inflated, leading to a larger value of R. The error arises from assuming that the gas has occupied the entire volume of the eudiometer tube, even though it has not.

b. If the balance used to weigh the magnesium gives a mass that is higher than the actual value, it would lead to an overestimate of the calculated value of R. This is because the molar amount of magnesium used in the reaction would be overestimated, resulting in a higher value of R. The error arises from using incorrect mass data, which directly affects the calculation of moles of magnesium.

c. If some H2 escapes into the beaker during the reaction, without being collected in the eudiometer tube, it would result in an underestimate of the calculated value of R. This is because the volume of gas collected would be smaller than the actual volume produced in the reaction. The error arises from a loss of gas during the experiment, leading to an incomplete collection of the produced gas.