Changing concentration of hydrochloric acid

Keywords: hydrochloric acid concentration effect, concentration change hydrochloric

How will changing the focus of hydrochloric (HCl) acid affect the rate of hydrogen gas (H2) production during the reaction with magnesium (Mg), using the pressure buildup by hydrogen gas?

Introduction

Factors that influence costs of reactions include modification in concentration, temperature, surface, or the addition of a catalyst. This experiment will particularly investigate the effect of concentration modification of the reactants upon the rate of reaction, applying hydrochloric acid and magnesium strip. The focus of HCl acid option is handled through serial dilution.

2HCl(aq) + Mg(s) → MgCl2(aq) + H2(g)

This experiment specifically will explore the way the pressure alterations as the above reaction proceeds. Because the response creates hydrogen gas as something, building up even more pressure within the confined space of a test tube, a pressure sensor will measure the rate of reaction. Following the reaction begins, approximately 20 seconds of info will be gathered with each trial, to be able to formulate a common style (a graph of pressure as time passes). With common slopes of different quantity of concentrations, a linear regression range will then be intended to sketch the trend, about the effect of concentration after pressure-the rate of response.

Hypothesis

According to Collision Theory, the reactant contaminants must collide together, and so creating a response. Because increasing the focus of HCl acid option also means an increase in the number of hydrogen and chloride ions, collision between your reactant particles increases as well, resulting in more products-hydrogen gas. With more production of hydrogen gas in the confined evaluation tube, pressure will establish.

Therefore, if-at a given period of time-the focus testmyprep of HCl acid answer increases, then your rate of reaction will increase accordingly, because more collisions will occur, creating hydrogen gas at a higher rate.

Variables

Variable description

Method of measuring variable

Dependent variable

Pressure buildup as a result of response between hydrochloric acid choice and magnesium

During the reaction, H2gas is developed, thus increasing the volume within the confined space of a test out tube and raising the pressure. This change will be documented by a pressure sensor. Collecting data for approximately 10 seconds prior to the injection of the magnesium strip, the measurement of pressure will continue for about 20 seconds following the reaction begins. Three trials will be required for each concentration of HCl solution to minimize random error.

Rate of reaction

Using the more appropriate initial rate of the reaction, about 10 secs of the graph after the reaction begins will be used to create a slope of modification in pressure over time.

Independent variable

Concentration of HCl solution

Using serial dilution along with apparatus such as micropipette and flask, the 1M hydrochloric acid answer will end up being diluted into 0.5M, 0.25M, 0.125M, and 0.0625M.

Controlled variables

Mg strip (length)

Using a ruler and scissor, the Mg strip will become cut into 15 pieces, each becoming 1cm.

Volume of hydrochloric acid solution

For each concentration, 3cm3of hydrochloric acid alternative is used, effectively measured by a pipette.

Temperature of reactants

The temperature remains frequent at room heat (approx. 25 degrees Celsius) throughout the whole experiment.

Shaking of the test tube

To create the virtually all accurate results feasible, physical motion when somewhat shaking the test tubes should be repetitive just as for each trial.

Size of the test out tube

Because several sizes of evaluation tubes would mean different volumes as well, constant size (volume) is vital, preferably small so that the reaction could be more conspicuous. To get this done, 15 identical check tubes are used.

Table 1: Set of Variables

Apparatus and Materials

1M hydrochloric acid solution

Distilled water

Magnesium strip

Flask (50cm3)

Pressure sensor

Logger Pro

Micropipette

15 identical check tubes

Sandpaper

Scissor

Procedure

Put 20cm3 of 1M HCL remedy in the flask and dilute it to 0.5M with 20cm3 of distilled water.

Using the serial dilution as in step one 1, prepare 10cm3 solutions with concentrations of 1M, 0.5M, 0.25M, 0.125M, and 0.0625M.

Add 3 cm3 of every solution into labeled evaluation tubes applying the micropipette.

Repeat step three 3 to get ready three test tubes of every solution (15 altogether)

Cut out the magnesium strip into 15 bits of 1cm and sand them with sandpaper.

Put the lower out magnesium strip in to the test tube with 1M HCl solution.

Then quickly go over the evaluation tube with the pressure sensor.

Start collecting info while shaking the evaluation tube in a constant manner for approximately 25 seconds after the reaction begins.

Repeat steps six to eight 8 for all other test tubes.

Data Collection and Processing

Quantitative Data

Hydrochloric acid focus / mol dm-3

Change in pressure as time passes / â-³kPas-1

Trial 1

Trial 2

Trial 3

1M

1.689

1.247

1.392

0.5M

0.4722

0.4956

0.5093

0.25M

0.153

0.2124

0.1907

0.125M

0.2359

0.3702

0.1105

0.0625M

0.02393

0.1285

0.2759

Table 2: Switch in pressure over time at diverse concentrations of HCl solution

Qualitative Data

After the injection of the magnesium strip in to the HCl solution, it effervesces and pressure within the test tube begins to develop.

With evaluation tubes of higher focus, the pressure appears to be larger within enough time limit and more bubbles form.

At the end of the response, the solution’s color evolved to transparent yellow.

The reacted solution (item) gives off a foul smell.

Processed Data

Concentration of HCl solution, mol dm-3

Calculation

Average rate of reaction, â-³kPas-1

1

= 1.4427

1.4427

0.5

= 0.4924

0.4924

0.25

= 0.1854

0.1854

0.125

= 0.2389

0.2389

0.0625

= 0.1428

0.1428

Table 3: Calculation of average rate of reaction

Data Presentation

1 0.5 0.25 0.125 0.0625

Figure 1: Graph of average rate of reaction, kPa s-1 against concentration of HCl alternative, mol dm-3

Uncertainties

Standard Deviation

Standard deviation was calculated and represented in the charge of reaction vs. focus graph as error pubs.

HCl concentration, mol dm-3

Change in pressure over time,

â-³kPas-1

Average rate of reaction,

â-³kPas-1

Standard deviation

Trial 1

Trial 2

Trial 3

1

1.689

1.247

1.392

1.4427

0.2253

0.5

0.4722

0.4956

0.5093

0.4924

0.01876

0.25

0.153

0.2124

0.1907

0.1854

0.03006

0.125

0.2359

0.3702

0.1105

0.2389

0.1299 testmyprep.com

0.0625

0.02393

0.1285

0.2759

0.1428

0.1266

Table 4: Regular deviation for different focus of HCl solution

Standard deviation was calculated by a graphing calculator.

Uncertainty due to the serial dilution of HCl solution

Uncertainty due to 1cm3

Uncertainty during dilution & measuring pressure (?)

Conclusion

In Figure 1, the pattern of several concentrations of reactants influencing the amount of reaction can be illustrated. The linear regression collection demonstrates the clear change in rate of response, in line with the change in concentration-the lower the focus, the slower the fee of reaction. Hence, the original hypothesis, stating the direct relationship between focus and rate of reaction, is justified and validated.

Evaluation

Shown by Table 4, where the standard deviations for each concentration of HCl option are calculated, the benefits of the experiment are fairly exact, but not to a great extent. Additionally, uncertainties created through the planning of the experiment, as with the operations of apparatus and supplies like the gas pressure sensor, flask, and micropipette decreases the accuracy. Although Physique 1, the graph including the general trend of concentration’s effect after the rate of reaction seems to validate the hypothesis, the rate of result of 0.25M HCl solution stands out of the tendency, decreasing the validity of the experiment’s results.

More elements that may contain hindered obtaining correct results of the experiment include:

Error

Impact

Improvements

Using hands to shake the test tubes for faster response rate

Any non-perceptible (by human beings) changes influenced each reaction to proceed differently, in the end creating different circumstances for each and every trial. This modification in circumstances is essential since it greatly hinders accurate benefits.

The usage of a vibration plate rather may reduce error since it is more constant. Reproducible circumstances could be better achieved.

.