Determination Of Water Hardness Research Articles

Correction to “The Laboratory Skills Contest: An Activity to Improve and Evaluate Students’ Laboratory Practice through the Determination of Water Hardness”

Correction to “The Laboratory Skills Contest: An Activity to Improve and Evaluate Students’ Laboratory Practice through the Determination of Water Hardness”

Teaching Reform of Analytical Chemistry Experiment and Theoretical Knowledge Integration Based on Problem-Based Learning: A Case Study of “Determination of Water Hardness”

Teaching Reform of Analytical Chemistry Experiment and Theoretical Knowledge Integration Based on Problem-Based Learning: A Case Study of “Determination of Water Hardness”

PELATIHAN KARYA ILMIAH PADA BIDANG KIMIA BAGI SISWA SMA PGRI JAYAPURA

Community service activities have been carried out at SMA PGRI Jayapura, Heram District, Jayapura City, Papua Province. The purpose of this service is to increase students' interest in chemistry through scientific papers training with simple research methods. The initial stage carried out in this activity is the socialization of scientific papers. The next stage is conducting simple research, processing data and training in writing scientific papers. The research topic chosen is the determination of water hardness by complexometry. During this activity the students were very enthusiastic and motivated. This can be seen when students listen to material explanations, discuss, conduct research and write reports. Based on the evaluation results, the success rate of this activity reached 80%. This is because there are still some students who have difficulty in processing data and writing reports. Therefore, the role of the teacher is very important in assisting students to increase interest and creativity in producing a scientific work.Keywords: training; scientific work; SMA PGRI Jayapura

Automatic Determination of Water Hardness by Vector Colorimetry with Acid Chrome Blue K

Automatic Determination of Water Hardness by Vector Colorimetry with Acid Chrome Blue K

A LOW-COST PAPER-BASED MICROFLUIDIC IMPEDIMETRIC DEVICEC FOR THE DETECTION OF WATER HARDNESS

A microfluidic paper-based impedimetric device was developed as a water hardness sensor. This device is capable of performing the analysis with a sample volume of few microliters with no prior treatments. A phenol-formaldehyde graphene electrode modified with ethylenediaminetetraacetate was used as the working electrode. Ag pseudo reference and carbon electrodes were used to fabricate the device. Current simultaneous metal ion detection sensors are based on complex and expensive electrode setups. The proposed inexpensive, quick and portable device is capable of detecting Ca2+ and Mg2+ simultaneously. Electrode double layer-based charge transfer resistance and the maximum negative imaginary impedance produced a linear correlation with each metal ion concentration. The calculated limits of detection for Ca2+ and Mg2+ were 0.31 and 0.24 ppm, respectively. A set of samples containing Ca2+ and Mg2+ with a hardness of 2 ppm (as calcium carbonate) were used to test the device. The proposed tool is suitable as a semi-quantitative device for the determination of hardness in water.

A LOW-COST PAPER-BASED MICROFLUIDIC IMPEDIMETRIC DEVICEC FOR THE DETECTION OF WATER HARDNESS

A microfluidic paper-based impedimetric device was developed as a water hardness sensor. This device is capable of performing the analysis with a sample volume of few microliters with no prior treatments. A phenol-formaldehyde graphene electrode modified with ethylenediaminetetraacetate was used as the working electrode. Ag pseudo reference and carbon electrodes were used to fabricate the device. Current simultaneous metal ion detection sensors are based on complex and expensive electrode setups. The proposed inexpensive, quick and portable device is capable of detecting Ca2+ and Mg2+ simultaneously. Electrode double layer-based charge transfer resistance and the maximum negative imaginary impedance produced a linear correlation with each metal ion concentration. The calculated limits of detection for Ca2+ and Mg2+ were 0.31 and 0.24 ppm, respectively. A set of samples containing Ca2+ and Mg2+ with a hardness of 2 ppm (as calcium carbonate) were used to test the device. The proposed tool is suitable as a semi-quantitative device for the determination of hardness in water.

Determination of the total hardness in tap water using acoustic wave sensors

Abstract The determination of hardness in water is a useful parameter to control the quality of water for households and industrial uses. The present work proposes a new methodology as an alternative to the conventional EDTA titration. The determination of Ca 2+ and Mg 2+ is performed using two different coated piezoelectric quartz crystals. Poly(vinyl chloride) membranes, incorporating a plasticizer and a Mg or Ca ionophore were used to coat the piezoelectric quartz crystals. Results obtained by this new methodology shows that the tap water found in Portugal can be considered soft in Gouveia (9.4 ± 0.8 mg L −1 CaCO 3 ) and in Vila Praia Âncora (15 ± 1 mg L −1 CaCO 3 ), slightly hard in Leiria (59 ± 1 mg L −1 CaCO 3 ), moderately hard in Aveiro (74 ± 1 mg L −1 CaCO 3 ) and in Esposende (104 ± 1 mg L −1 CaCO 3 ) and very hard in Tomar (225 ± 1 mg L −1 CaCO 3 ). The results obtained by the proposed method are not significantly different ( α = 0.05), both in terms of accuracy and precision, from the ones obtained by the conventional EDTA titration method. Besides providing individual concentration of Ca 2+ and Mg 2+ , this new methodology also has the advantage of being less reagent, sample and time consuming.

Determination of water hardness by flow Injection spectrophotometry

Determination of water hardness by flow Injection spectrophotometry

The flat surfaced membrane coated mercury electrode as analytical tool in the continuous voltammetric analysis

Specific analytical problems often arise which can be easily solved if a mercury electrode of constant surface area is used as voltammetric sensor. In this work a membrane covered mercury electrode was prepared and used in solving various analytical tasks. One of them was the determination of water hardness. A sample injection method was developed applying EDTA reagent and a flow-through analytical system. Two different voltammetric enzyme electrodes (measuring glucose and L-amino acid) were prepared by using the membrane covered mercury electrode as base sensor. The application of the enzyme electrode in flow-through circumstances was proved to be very advantageous in determining selectively L-DOPA in the presence of the D-form.

The flat surfaced membrane coated mercury electrode as analytical tool in the continuous voltammetric analysis

Specific analytical problems often arise which can be easily solved if a mercury electrode of constant surface area is used as voltammetric sensor. In this work a membrane covered mercury electrode was prepared and used in solving various analytical tasks. One of them was the determination of water hardness. A sample injection method was developed applying EDTA reagent and a flow-through analytical system. Two different voltammetric enzyme electrodes (measuring glucose and L-amino acid) were prepared by using the membrane covered mercury electrode as base sensor. The application of the enzyme electrode in flow-through circumstances was proved to be very advantageous in determining selectively L-DOPA in the presence of the D-form.

The complexometric determination of Ca based on the concentration-dependent distribution using90Sr and a cation exchanger

The method described enables the determination of about 8·10−5 Ca which compares favourably with published data obtained by other radiometric methods. In 3 ml solution 0.1 mg of Ca can be determined with a precision of ±1.5%. Iron does not interfere in moderate concentrations. The method can also be used for the determination of water hardness in the case of very low hardness values or in turbid or coloured solutions.

Automated Simultaneous Determination of Water Hardness, Specific Conductance and pH

Abstract An automated method of determining water hardness, specific conductance and pH in natural water samples is described. The method uses simultaneous measurements of the divalent cation activity, conductivity and pH of the sample. The automated apparatus, which is programmable, consists of a sample changer, electrode assembly, activity and conductivity meters, minicomputer and control module. The apparatus produces direct print-out of water hardness, specific conductance and pH and the optimum sampling rate is 20 samples per hour. A comparison of this method with standard methods is given. Known addition, known dilution technique is used to eliminate the interference of carbonate ion due to the complexation of calcium.

A Simple Microtitration Method for the Determination of Calcium and Magnesium in the Hæmolymph of Insects

ACCORDING to several authors1,2, the direct titration of calcium and magnesium with ethylene-diamine tetraacetate has yielded very good results, especially in the determination of water hardness and in clinical investigations of blood plasma. Since other methods described for the determination of calcium and magnesium are rather laborious, and micro-scale determination is liable to large errors, we have tried the direct titration with ethylene-diamine tetraacetate using the well-known Linder-strom–Lang micro-titration technique. Determinations have been carried out on some species of Blattaria: Periplaneta americana, Periplaneta australasiae and Blabera fusca.