What is the precipitate of cobalt II hydroxide?
Cobalt (II) hydroxide precipitates as a solid when an alkali metal hydroxide is added to an aqueous solution of Co 2+ salt. For example, 3 as both the base and a complexing agent.
What happens when sodium hydroxide reacts with cobalt 2+?
To the Co 2+ ion solution a few drops of the sodium hydroxide solution were added via a pipette. The OH- ions from the sodium hydroxide react with the cobalt 2+ ions to form cobalt (II) hydroxide. This is the coloured precipitate that you are looking for. The formula of the cobalt (II) hydroxide is Co (OH)2.
Can mixed nickel–cobalt hydroxide precipitate be acid leached?
A new method for acid leaching mixed nickel–cobalt hydroxide precipitate (MHP) is proposed; whereby nickel is largely dissolved while cobalt and manganese are stabilised in the solid phase by preferential oxidation. The relevant oxidation thermodynamics are presented.
What is cobalt 2 hydroxide used for?
This compound is blue and rather unstable. Cobalt(II) hydroxide is most used as a drying agent for paints, varnishes, and inks, in the preparation of other cobalt compounds, as a catalyst and in the manufacture of battery electrodes.
Is cobalt a precipitate?
The reaction of hexaaquacobalt(II) ions with carbonate ions You simply get a precipitate of what you can think of as cobalt(II) carbonate. The the precipitate is better described as a basic carbonate with a formula of the type xCoCO3,yCo(OH)2,zH2O.
Is cobalt two hydroxide soluble in water?
Cobalt(II) hydroxide Properties Soluble in acids and ammonia. Very slightly soluble in water. Insoluble in dilute alkalis.
Does cobalt chloride and sodium hydroxide form a precipitate?
Here, sodium hydroxide (NaOH) is added to cobalt(II) chloride (CoCl2). The result is a red solution and a blue-green precipitate.
Is cobalt III hydroxide aqueous?
The brownish-black form is a stable solid and can be prepared by reaction of water solutions of cobalt(II) chloride and sodium hydroxide, followed by oxidation with ozone....Cobalt(III) hydroxide.NamesIUPAC name Cobalt(III) hydroxideOther names Cobaltic hydroxideIdentifiersCAS Number1307-86-420 more rows
Is CU OH 2 soluble or insoluble?
Copper (II) hydroxide has some small solubility in water, determined by its solubility product constant. More importantly, it will dissolve freely and act as a base if a suitable acid, such as acetic acid, is is available to be neutralized.
Is Cobalt soluble in water?
Chemical properties Pure cobalt does not dissolve in water, but will dissolve (or react) with acids. It will burn when exposed to heat. The fumes may be hazardous. Compounds that are not soluble in water are cobalt carbonate and cobalt oxide.
Does cobalt and ammonia form a precipitate?
Cobalt(II) Chloride with Ammonia The result is a blue-green precipitate.
What type of reaction is cocl2 and NaOH?
0:013:49How to Write the Net Ionic Equation for CoCl2 + NaOH = Co(OH)2 + NaClYouTubeStart of suggested clipEnd of suggested clipIn this video we'll write the balanced molecular equation for cocl2. Plus naoh this is copper iiMoreIn this video we'll write the balanced molecular equation for cocl2. Plus naoh this is copper ii chloride plus sodium hydroxide.
Does cobalt react with NaOH?
Here, sodium hydroxide (NaOH) is added to cobalt(II) chloride (CoCl2). The result is a red solution and a blue-green precipitate.
What type of reaction is cobalt III hydroxide?
0:001:22How to Write the Formula for Cobalt (III) hydroxide - YouTubeYouTubeStart of suggested clipEnd of suggested clipThis is one you really need to remember this is a polyatomic ion it's o h. Minus. So the whole o hMoreThis is one you really need to remember this is a polyatomic ion it's o h. Minus. So the whole o h that's oh minus since we have a metal and a group of nonmetals we have an ionic compound.
Is Co soluble or insoluble in water?
The bond between carbon and oxygen is not as polar as the bond between hydrogen and oxygen, but it is polar enough that carbon dioxide can dissolve in water.
Is Ca OH 2 aqueous or solid?
Calcium Hydroxide - Ca(OH)2. Calcium hydroxide, commonly referred to as slaked lime, is described by the chemical formula Ca(OH)2. It is an inorganic compound which has a white, powdery appearance in its solid-state.
What is the reaction of hexaaquacobalt(II) ions with hydroxide
Hydroxide ions (from, say, sodium hydroxide solution) remove hydrogen ions from the water ligands attached to the cobalt ion. Once a hydrogen ion has been removed from two of the water molecules, you are left with a complex with no charge - a neutral complex.
What happens when you add hydrochloric acid to a solution?
If you add concentrated hydrochloric acid to a solution containing hexaaquacobalt(II) ions, the solution turns from its original pink colour to a rich blue. The six water molecules are replaced by four chloride ions. The reaction taking place is reversible.
What is the reaction between ammonia and hydrogen peroxide?
With ammonia solution and hydrogen peroxide. The reaction with ammonia solution followed by hydrogen peroxide produces the same dark reddish-brown solution as before - only faster. The equation for the oxidation of the ammine complex is:
Is hexaamminecobalt yellow?
In fact the hexaamminecobalt(III) ion is yellow! What you see is a mixture of this ion and various other cobalt(III) ions involving ligand exchange reactions with both water molecules and negative ions present in the solution. Another oxidation of hexaaquacobalt(II) ions.
Is hexaaquacobalt a base or ligand?
Reactions of hexaaquacobalt(II) ions with ammonia solution. The ammonia acts as both a base and a ligand. With a small amount of ammonia, hydrogen ions are pulled off the hexaaqua ion exactly as in the hydroxide ion case to give the same neutral complex. That precipitate dissolves if you add an excess of ammonia.
Is blue precipitate a ligand?
One reliable source quotes it vaguely as a change in coordination of the metal ion. Another suggests that the blue precipitate involves a chloride ion (from the cobalt(II) chloride solution if that's what you used) as a ligand. You are unlikely to need to worry about this at this level.
Can you add hydrogen peroxide to hexaaquacobalt?
Another oxidation of hexaaquacobalt(II) ions. Rather than relying on oxidation by the air, you can add an oxidising agent such as hydrogen peroxide. You can do this after the addition of ammonia as in the last case, or you can do it following addition of sodium hydroxide solution.
What is MHP in mining?
Mixed nickel-cobalt hydroxide precipitate (MHP) is a relatively recent intermediate product in primary nickel production. The material is now being produced on a large scale (approximately 60,000 t/y Ni as MHP) at facilities in Australia (Ravensthorpe, First Quantum Minerals) and Papua New Guinea (Ramu, MCC/Highlands Pacific). The University of Queensland Hydrometallurgy research group developed a new processing technology to refine MHP based on a selective acid leach. This process provides a streamlined route to obtaining a high purity nickel product compared with conventional leaching / solvent extraction processes. The selective leaching of nickel from MHP involves stabilising manganese and cobalt into the solid phase using an oxidant. This paper describes a batch reactor study investigating the timing of acid and oxidant addition on the rate and extent of nickel, cobalt, manganese leached from industrial MHP. For the conditions studied, it is concluded that the simultaneous addition of acid and oxidan...
What are precipitation diagrams?
Precipitation diagrams illustrate the solubility behaviours of metal hydroxides, sulphides, arsenates and phosphates in aqueous solutions; they show the relative solubilities of the four types of metal salts considered and they also enable the theoretical solubilities of the metal salts to be estimated at any pH in the acidic region. The methods of construction and use of the diagrams are discussed and their limitations are outlined.
Abstract
A new method for acid leaching mixed nickel–cobalt hydroxide precipitate (MHP) is proposed; whereby nickel is largely dissolved while cobalt and manganese are stabilised in the solid phase by preferential oxidation. The relevant oxidation thermodynamics are presented.
1. Introduction
Hydrometallurgical processing of nickel laterite ore is complicated by impurities such as chromium, iron, aluminium, manganese and cobalt. Cobalt, in particular, is a value metal which is always present in the unweathered precursor igneous rock ( Freyssinet et al., 2005 ).
4. Conclusions
The selective acid leaching of MHP provides a relatively simple means to recover and separate nickel from cobalt, manganese, copper and iron. These separations were achieved quickly (< 1 h) over a wide range of temperature (30–80 °C). Nickel leaching was only slightly affected by MHP ageing.
Acknowledgements
The authors gratefully acknowledge the financial assistance for this research provided by the Queensland Department of Employment, Economic Development and Innovation, as well as support from UniQuest.
