Cumulative AP Chemistry Hamann Lab I

Unknown Solutions Possible Identification + Reason(s). (Document Created by: RED)
Example Unknown

● (1) I believe this solution to be Copper(II)Hydroxide because of the following reasons:
○ It has a pH value of 12 and burning it produces a blue­green color. ○ It produced bubbles when mixed with Zn, Al and Fe which are all more reactive than copper.
● (2) I believe this solution to be Sodium Sulfate because of the following reasons:
○ Blah blah blah
○ Blah blah
○ blah blahhh

Unknown 1

● NaCl
○
○
○
○
○

Unknown 2

yellow flame
7 ph precip with agno3 therefore one of the halides (cl, br, i) white solid from evaporation conductive ● Water
○ no residue when evaporated
○ almost neutral ph
■ ^my group got pH 9 tho??
○ no conductivity­ there was conductivity for 2 contamination could have been present causing the conductivity

Unknown 3

● NiCl2 or CuCl2
○ i dont think its copper cuz of color of solution
○ I think that it can be NiCl2 or NiSo4 cuz Ni turned blue in presence of ammonia (i think only periods 1 and 2 can use this) ○ Was solution 3 soluble or insoluble in Bacl2 and Agno3?
That can help us decide whether its cl2 or so4. bacl was precipitate ■ precipitate in bacl2 and naoh
■

Unknown 4

● CuSo4
○ bacl2 precip means so4
○ blue color means copper

○ also paperclip looked copper colored when left in this solution ●
Unknown 5

● NH4NO3 or NH4Cl
○ nh4cl most likely
○ i agree with nh4cl
○ Reasoning?
○ if it was nh4no3 it would not form precipitate when you add agno3 im pretty sure
○ What else can we say about NH4Cl?
○ was there bubbles with hcl? if so, then it can be co3 2­
(carbonate)
●

Unknown 6

● KOH
○ basic
○ flame test
○ did not react with naoh therefore it can contain oh, i guess
●

Unknown 7

● HCl
○
○
○
○
●

Unknown 8

● Ca(OH)2
○ was soluble with naoh therefore