Select the cations responsible for water hardness.1) Ca2+ 2) CO3−2 3) CaCO3 4) Mg2+
Select the cations responsible for water hardness.1) Ca2+ 2) CO3−2 3) CaCO3 4) Mg2+
Determine the hardness of this water in units of mg/L as CaCO3. Hardness is the sum of the concentrations of multivalent cations in the water, which in this case include Ca (as Ca2+) and Mg (as Mg2+). Hardness is expressed in “equivalent” units or “CaCO3” units.
The total hardness a water sample is 200 mg/l as CaCO3. The calcium (Ca2+) concentration is 50 mg/l. Calculate the magnesium (Mg2+) concentration, in mg/l.
Hardness in groundwater is due to the presence of metal ions, primarily Mg2+ and Ca2+. Hardness is generally reported as ppm CaCO3. To measure water hardness, a sample of groundwater is titrated with EDTA, a chelating agent, in the presence of the indicator Eriochrome Black T, symbolized as In. Eriochrome Black T, a weaker chelating agent than EDTA, is red in the presence of Ca2+ and turns blue when Ca2+ is removed. red blue Ca(In)2+ +EDTACa(EDTA) 2+ In A 50.00...
Groundwater is defined by the following analysis: Ca2+ = 80 mg/L as Ca2+ Mg2+ - 55 mg/L as Mg2+ HCO3-350 mg/L as CaCO3 pH = 8.0 FORMULA CaCO3 Ca2+ Mg2+ EQUIVALENT WEIGHT (g/EW 50 20 12.2 61 HCO3 mg as CaCO3 L mg Equivalent Weight of CaCo3 (g/EW) as species X L Equivalent Weight of Species (g/EW) Noncarbonate hardness (NCH) of the raw water, in mg/L as CaCO3, is: 1) 55.0 2) 76.3 3) 135.0 4) 200.0 5) 350.0
Water Hardness by EDTA Titration Objective: To determine [Ca2+,MG2+] and [Mg2+] concentration in an unknown water sample A 0.0107 molarity solution of EDTA is prepared for the experiment. 25 mL of an unknown is pipetted and diluted 100 mL with distilled water and adjusted to a pH between 8 and 10 with NH4OH. A 10.00 mL portion of the diluted unknown is transferred to a 250 mL flask with 3 mL of pH 10 ammonia buffer and tiny amount of...
If a sample of tap water contains 400 ppm of Ca2+ and 80 ppm of Mg2+, what is the hardness of this water sample in terms of equivalent concentration CaCO3, in mg/L?
Hardness in groundwater is due to the presence of metal ions, primarily Mg2 and Ca2t. Hardness is generally reported as ppm CaCO3. To measure water hardness, a sample of groundwater is titrated with EDTA, a chelating agent, in the presence of the indicator eriochrome black T, symbolized here as In. Eriochrome black T, a weaker chelating agent than EDTA, is red in the presence of Ca2 and turns blue when Ca2+ is removed. red blue Ca(ln)2+-EDTA → Ca(EDTA,-+ + In...
Calculate the hardness of water in units of mg/L of Caco3 (see equation 15-7) if your titration at pH 10 resulted in a concentration of 15 mmol/L. Round your answer to the nearest whole number and enter only the numerical answer into the box. In most natural waters, some magnesium ion is present, so expressing water hardness in units of mg/L of CaCO3 is an arbitrary convention that has been adopted for the sake of convenience (or tradition). The conversion...
25.8 EXPERIMENT 4: DETERMINATION OF WATER HARDNESS DATA SHEET PART II: TESTING FOR TOTAL WATER HARDNESS 0.0100M Concentration of EDTA used Sample 1 25.0 22.35 22.15 Sample 2 25.0 21.7. Sample 3 35.0 21.7 Vol Hard Water Solution Vol EDTA Moles EDTA Average Moles EDTA Moles of Ca2+ Moles of CaCO3 Mass of CaCO3 Mass of Hard Water Solution Total Hardness (ppm)
Hard water normally contains mineral ions, such as Ca2+ and Mg2+ ions, from minerals that dissolved in the ground water. For water of low hardness, the concentration of Ca2+ ions is usually expressed as ppm CaCO3 in the water sample. Parts per million (ppm) is defined as one part of solute mass per 1,000,000 parts of solution mass, as shown in the following equation. Please note, the unit of denominator and numerator needs to be the same. Since ppm expresses...