Is it normal to get a black precipitant when oxidizing Al in a NaOH solution?
374481
It is quite normal. I use this process a lot for creating hydrogen in my lab for demonstrations. I fill up balloons and blow them up. Students love it.The black precipitate is a complex hydroxide of sodium and aluminum.
646111
You can turn it black with an iodine solution, then turn it back with sodium thiosulphate solution. Neat trick.
945837
Sulphide at th correct pH will precipitate NiS before MnS.\n\nIn your case, and excess of ammonia will form a soluble Ni complex and only precipitate Mn as the hydroxide. On boiling the Mn(OH)2 will probably oxidise to black MnO2.\n\nAding NaOH to both in excess will dissolve Al(OH)3 but Mn(OH)2 so you could use this test to tell the respective chlorides apart.
975769
Al(s) + MnO4- (aq) -----> MnO2 (s) + Al (OH)4- (aq)\n\nSplit the above into two half equations:\n\n1) Al(s)  --->  Al (OH)4- (aq)  and\n2) MnO4- (aq) -----> MnO2 (s)\n\nBalance 1) as follows:\n\n1) 4OH^-  +  Al(s)  --->  Al (OH)4- (aq) now balance for charge:\n1) 4OH^-  +  Al(s)  --->  Al (OH)4- (aq)  +  3e^-\n\nBalance 2) as follows:\n2) MnO4- (aq) ---> MnO2 (s)  +  2H2O (l) (turn xs O into H2O)\nNow balance with H^+:\n2) 4H^+  +  MnO4- (aq) ---> MnO2 (s)  +  2H2O (l)\nnow balance charge:\n2) 3e^-  +  4H^+  +  MnO4- (aq) ---> MnO2 (s)  +  2H2O (l)\n\nNow add 1) and 2) (electrons happen to be equal):\n4OH^-  +  Al(s)  +  4H^+  +  MnO4- (aq) ---> MnO2 (s)  +  2H2O (l)  Al (OH)4- (aq)\nnow OH^-  +  H^+  ---> H2O:\n\n4H2O  +  Al(s)    +  MnO4- (aq) ---> MnO2 (s)  +  2H2O (l)  Al (OH)4- (aq)\n\nSubtract 2H2O from both sides:\n2H2O (l)  +  Al(s)    +  MnO4- (aq) ---> MnO2 (s)  +    Al (OH)4- (aq)\n\nI hope that helps. If you need more help, please email me or re post.
196165
NaHSO4 itself is acidic, so the solution's color should be yellow due to the bromcresol green being in the presence of acid
857117
Run a borax bead test...for info see:\nhttp://en.wikipedia/wiki/borax_bead_test\n\nOr, iron ppts out as its hydroxide...a flocculent ppt... in basic soln, while sodium does not. Dissolve some in water and slowly add NaOH soln, watching for ppt.  This is only good if you are CERTAIN that spl contains only Fe or Na.
471546
A.  Iodine is being reduced from +5 in HIO3 to 0 in I2; oxygen is being oxidized from -1 in H2O2 to 0 in O2.\n\nB.  There is no oxidation/reduction going on; this is simple metathesis, producing the barium sulfate precipitate.
38065
There are innumerable soluble salts of organic and inorganic compounds. For some soluble salts, there will be no precipitate when sodium hydroxide is added. You can consider sodium acetate as one example of this but there are many many others. \nFor some soluble salts, there will be a precipitate when sodium hydroxide is added to solution. The appearance of the precipitate depends on the nature of the salt. For some soluble salts, such as ammonium hydroxide, the addition of sodium hydroxide will evolve ammonia as a gas. That reaction is part of the classical determination of protein in nutritional laboratories.
8783
It depends on what you are adding the NaOH to.  If you add NaOH to pure H2O the ideal solution mixture will become more alkaline...i.e. higher pH.  If you add NaOH to a stronger organic base such as an Azide (N3-) the solution will be come more acidic...i.e. lower pH.
423114
Adding sulphuric acid and sodium hydroxide respectively??
682281
not really sure why, but if you let air get to vanilla, it turns to a darker color. so it probably has some kind of preservative in it making it that way...( just a guess)
570619
no this is incorrect\n\nsodium hydroxide will ionise in water to produce sodium+ ions and Hydroyl (-ve) ions\nso\n\nthewater is not truely a reagent in this reaction,  it is simply the solvent\n\nNaOH + H2O -> Na(+)aq + OH(-)aq\n\nthe aq after an ion indicates it is in aqueous solution (ie in water\nions charges should be written in superscript after the ion (ie above and after) - not in brackets
476397
bubbling the O2/Cl2 mixture through aqueous NaOH will remove the Cl2.  it reacts to give bleach ... NaOCl ... (and salt and water).  assuming you didn't want the Cl2 ;-)
773341
No precipitate is formed.\nYou will see bubbles of carbon dioxide if there is enough HCI (Na2CO3+2HCI=2NaCI+H2O+CO2). If there isn't enough HCI ,Na2CO3+HCI=NaHCO3+NaCI happens ,you will see nothing.
22203
AL2 O3 (Aluminum oxide)
853471
normally they form hydroxides, but oxides are possible.  either would be considered basic
537646
The thing is that iron III hydroxide isn't soluble in water.  It just sits there and doesn't make many hydroxide ions, which are necessary for a strongly basic solution.  Barium hydroxide, however, is soluble and breaks up into barium ions and hydroxide ions, giving a strongly basic solution.