Standart pH bufer eritmasi nima? Uning xususiyatlari qanday?
PH bufer eritmasi pH qiymatini barqaror ushlab turadigan eritmadir. Agar bu eritmaga oz miqdorda kislota yoki gidroksidi qo'shilsa yoki eritmadagi kimyoviy reaksiya oz miqdorda kislota yoki ishqor hosil qilsa va eritma mos ravishda suyultirilsa, eritmaning pH qiymati asosan barqaror bo'lib, u qarshilik ko'rsatishi mumkin. oz miqdorda kislota. Asos katta yoki suyultirilganda pH qiymati o'zgarmaydigan eritma bufer eritma deyiladi.
Standart pH buferi quyidagi xususiyatlarga ega:
(1) Standart eritmaning pH qiymati ma'lum va belgilangan aniqlikka etadi;
(2) Standart eritmaning pH qiymati yaxshi takrorlanuvchanlik va barqarorlikka ega, katta bufer sig'imi, kichik suyultirish qiymati va kichik harorat koeffitsientiga ega;
(3) Eritmani tayyorlash usuli oddiy;
2. pH standart bufer eritmasi qanday tayyorlanadi?
Umumiy pH o'lchash uchun pH guruhi reagentlarining to'liq to'plami (250 ml tayyorlanishi mumkin) ishlatilishi mumkin. Eritmani tayyorlashda erigan karbonat angidridni olib tashlash uchun deionizatsiyalangan suvni ishlatish va oldindan 15-30 daqiqa davomida qaynatish kerak. Plastik paketni kesib oling va reagentni stakanga quying, uni kerakli miqdorda deionizatsiyalangan suv bilan eritib oling, sumkani yuving, so'ng uni 250 ml hajmli o'lchov kolbasiga quying, belgigacha suyultiring va yaxshilab silkiting.
3. PH bufer eritmalarini qanday to'g'ri saqlash va ishlatish kerak?
After the buffer solution is prepared, it should be placed in a glass bottle or polyethylene bottle (alkaline pH buffer solutions, such as pH=9.18, pH=10.01, pH=12.46, etc., should be placed in polyethylene bottles) with the bottle cap tightly closed. , stored in the refrigerator at low temperature (5-10℃), it can generally be used for about six months. If the mixer is found to be turbid, moldy or precipitated, it cannot be used further. When using, several 50mL polyethylene vials should be prepared, pour the combined solution in the large bottles into the vials, and leave them at ambient temperature for 1 to 2 hours, and wait for the temperature to balance before use. Do not pour it into a large bottle after use to avoid contamination. The buffer solution in the bottle can be used for 2 to 3 days under environmental conditions >10 daraja. Umuman olganda, pH=7.00, pH=6.86 va pH=14.00 ning uchta eritmasi sifatida foydalanish mumkin. uzoqroq vaqt davomida pH=9.18 va pH{9}}.01 eritmalarining pH qiymatini havodagi karbonat angidridning singishi tufayli oʻzgartirish osonroq.
