Be sure to answer all parts. a buffer is prepared by mixing 50.0 ml of 0.050 m sodium bicarbonate, nahco3, and 10.7 ml of 0.10 m naoh. (ka = 4.7 * 10-11) what is the ph?

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12 July, 18:24

Be sure to answer all parts. a buffer is prepared by mixing 50.0 ml of 0.050 m sodium bicarbonate, nahco3, and 10.7 ml of 0.10 m naoh. (ka = 4.7 * 10-11) what is the ph?

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Meadow Levine · Answer 1

Moles HCO3 - = 0.0500L*0.050M = 0.0025

Moles OH - added = 0.0107L*0.10M = 0.00107

Moles CO32 - forms = 0.00107

Moles HCO3 - in excess = 0.0025-0.00107=0.00143

Total volume = 10.7 + 50.0 = 60.7mL = 0.0607L

[HCO3-] = 0.00143 / 0.607 = 0.0236M

[CO32-] = 0.00107/0.0607 = 0.0176M

pKa = 10.3

PH = 10.3 + log 0.0176/0.0236 = 10.2.