Question

Problems 1. Oxalic acid dihydrate, HyC204 2H20, is often used as a primary standard for the standardization of base solutions. For a procedure comparable to this experiment, approximately how many grams of oxalic acid dihydrate should be used in order to have a volume of about 15 ml of NaOH solution (approximately 0.15M) for the titration? The acid is diprotic (two H react) 15mL x L x 0,15 mol NaOH = 2.25x10 mol NIDH 1000mL IL. 2.25x10 m Worx Ima H594 =1.125x10 HG04:2H0 x 12619 H₃ (204.240.10.142, Growlot Tmal H49.240 2. How would the observed molarity of your experiment be affected by the following circumstances (ie, would it be higher than the true value, lower than the true value or remain unchanged)? Give your reasons. a) The potassium hydrogen phthalate is dissolved in more than 50 mL of water. The moonty but be lover because there are less moles of kHP per liter. b) The potassium hydrogen phthalate in the reagent bottle in the laboratory has been left open on a humid day and the potassium hydrogen phthalate has absorbed some moisture before you removed your sample of the acid. The molarity will remain unchanged because the sample was taken after and will be the same throughout. c) While swirling the flask during the titration, some of the liquid splashed out before the end point was reached. The molarity will be higher because the concentration of moles is more in Smallor Volume w would the equivalent weight be affected by the following circumstances (i.e. will it be higher than the true value, lower than the true value or remain unchanged). Give reasons for your answers. a) The burette is washed with distilled water but not rinsed with base. It will be b) A small amount of weighed acid was spilled during the transfer from the weighing vial. It will be less because it will contain less grams per mole. c) The weighed acid is transferred to a wet Erlenmeyer flask. It will
Can I get help with 3 please, but may you please check my responses for 1 & 2.

Answer 1

According to Chegg Policy only 1 question per post is allowed. please post the rest question seperately. Hence I am solving what you have asked

Hope you understand!!

SOLN 3

A...since you have rinsed only with water hence titrant will be diluted slightly hence giving result slightly high, which will give errorneously high value for the equivalent weight of the acid.

B......The titration value will be too low, giving errorneously low value for the EW of the acid.

C......It will have No effect, since all the acid is still being used in the titration procedure

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