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standard solution q (1 Viewer)

kkk579

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how would the concentration of the standard sol be affected if the volumetric flask had been rinsed with de ionised water before use and droplets of water were left in the flask when the sodium carbonate was added?

searched it up and ppl said that the calculated concentration would be lower than its literature value due to dilution, but i dont get this? you would have to rinse out the beaker with more de ionised water anyways and pour this into the volumetric flask up until the calibration line so even if u left the water in after rinsing the flask wouldnt this mean youd just be pouring in less de ionised water when rinsing out the beaker? since its only up to a specific line anyways so wouldnt the mols of solute and volume of solvent be the same regardless? therefore no change in concentration? if smo could clear this up or correct me if im wrong that would be great. thank you!
 

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how would the concentration of the standard sol be affected if the volumetric flask had been rinsed with de ionised water before use and droplets of water were left in the flask when the sodium carbonate was added?

searched it up and ppl said that the calculated concentration would be lower than its literature value due to dilution, but i dont get this? you would have to rinse out the beaker with more de ionised water anyways and pour this into the volumetric flask up until the calibration line so even if u left the water in after rinsing the flask wouldnt this mean youd just be pouring in less de ionised water when rinsing out the beaker? since its only up to a specific line anyways so wouldnt the mols of solute and volume of solvent be the same regardless? therefore no change in concentration? if smo could clear this up or correct me if im wrong that would be great. thank you!
Can't you just lace to avoid allat?
 

Average Boreduser

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It's like rinsing with a tiny bit of the same solution then discarding it. This helps to remove residual water or contaminants. My teacheer calls it lacing because it kinda is like what you do w a glass of beer and the foam starts to make rings on the cup, highlighting that the foam had distributed onto the surfaces of the glass
 
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how would the concentration of the standard sol be affected if the volumetric flask had been rinsed with de ionised water before use and droplets of water were left in the flask when the sodium carbonate was added?

searched it up and ppl said that the calculated concentration would be lower than its literature value due to dilution, but i dont get this? you would have to rinse out the beaker with more de ionised water anyways and pour this into the volumetric flask up until the calibration line so even if u left the water in after rinsing the flask wouldnt this mean youd just be pouring in less de ionised water when rinsing out the beaker? since its only up to a specific line anyways so wouldnt the mols of solute and volume of solvent be the same regardless? therefore no change in concentration? if smo could clear this up or correct me if im wrong that would be great. thank you!
Also, for the purpose of a depth study, its reasonable to keep the water in as the overall concentration wont be that far off.
 

wizzkids

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how would the concentration of the standard sol be affected if the volumetric flask had been rinsed with de ionised water before use and droplets of water were left in the flask when the sodium carbonate was added?
ANSWER: no effect on the concentration of the standard solution. The two critical parameters for making a standard solution are you must have an accurate number of moles inside the flask, and the volume must be made up to the scribe mark with distilled (or deionised) water. The temperature of the solution should be 20oC for greatest accuracy (because the volume of water changes as temperature changes).
 
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kkk579

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ANSWER: no effect on the concentration of the standard solution. The two critical parameters for making a standard solution is you must have an accurate number of moles inside the flask, and the volume must be made up to the scribe mark with distilled (or deionised) water. The temperature of the solution should be 20oC for greatest accuracy (because the volume of water changes as temperature changes).
Yeah exactly thats what i thought too, but i searched it up and multiple answers said it would lead to an underestimation of the true concentration
 

wizzkids

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Yeah exactly thats what i thought too, but i searched it up and multiple answers said it would lead to an underestimation of the true concentration
If that's exactly what those authors said about preparing a standard solution, well their opinions are wrong.
 

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