About 6 years ago, I made a precipitate of Lead Iodide in water by mixing Potassium Iodide and Lead Nitrate.
I have kept the precipitate in a test tube.
Would anybody know how stable is the precipitate over time. The temperature has been mostly between 20 and 32 degrees depending on the...
proteins are very complex molecules. but i think it would not be impossible to predict the molecular shape of glucose or an amino acid. you just have to start systematically, say from one of the Carbon atoms, and proceed then with the other bonds. These molecules do not have too many atoms.
Zn, HCl and CuSO4 works, i remember my teacher saying it.
and of course ZN++ does not REACT with Cl-, the ions remain in solution because ZnCl2 is a strong electrolyte.
but there has to be a way for Cu to get back to Cu++ and H+ to get to H2.
i guess this is what happens...
the Cu++ is reduced by zinc to Cu and the zinc is oxidised to Zn++. the Zn++ reacts with the Cl-.
the Cu is then oxidised back to Cu++ by H+ which gets reduced to H2
overall reaction: Zn + 2HCl -----> ZnCl2 + H2
basically it says that, the enthalpy change of a reaction depends only on the initial and final conditions of the reactants and products respectively. the reaction route or reaction pathway has no effect on the enthalpy change.
a quick example is when you produce CO2 from Carbon and oxygen...
there is covalent bonding. it is a macromolecule. and has very high melting point, it should be quite stable then, at least thermally...
i'm assuming you are talking about SiO2, because i never heard of SiO4. i kno that SiO2 is just the ratio of Si to O, and that SiO4 units are joined together...
you might also find a way to test for bacteria or germs (or living organisms in general) present. i dunno, maybe using microscopes??!
and for minerals and nutrients?? do plants getting tap water or bottled water grow differently??
if you store tap water and bottled water in a certain recipient...
there is the cracking of large alkane molecules, to give smaller ones in the petroleum industry. you only need a catalyst, silica or alumina, and a temperature of about 450 degrees.
for converting lower alkanes molecules to larger ones, i have no clue.
no, i don't think so. the elements in the periodic table exist throughout the universe. except the man made ones.
now, if the question is asking for elements present on another planet, then it might not be as much as many as found here. or you might even have elements which are not found on...
actually BaCO3 and BaSO3 react with the acid, to give CO2 and SO2 respectively. BaSO4 doesn't react. You may think of it like H2SO4 is a stronger acid than HCl, hence the HCl cannot displace the SO42-.
and i agree with symbolipoint about the complexes.
if I'm not wrong, this reaction ain't supposed to be occurring. H2 will not react with Cu2+.
you can't determine enthalpy change of formation in this reaction. the enthalpy change of formation is when 1 mol of a compound is produced from its elements in their elemental states.
AgNO3 will help you to find out if there are halide ions (chloride, iodide, bromide,..) in the salts X and Y.
BaCl2 will tell you if sulphate is present.
These two tests determine the anions.
the test with NaOH will help to distinguish the cation.
and i think Y is MgCl2 or MgSO4. you will...
iodide from excess KI is a reducing agent, it is oxidised by the hypochlorite ion to iodine. Iodine is an oxidsing agent. The iodine liberated will then oxidise the thiosulphate.
Iodine is normally brown when in solution. actually it reacts with iodide from the excess KI to form tri iodide...
hydrogen bonding is an INTERMOLECULAR FORCE (even if we call it H-bond), it occurs between molecules, such as water or ammonia. it is in no way an actual bond.
actually electronegativity sums the atomic size. The fatter the atom, the smaller is the electronegativity and vice versa.
i suppose you have to calculate the atomic mass of the element??! huh
let's take the example of chlorine, which has two istopes too. Cl-35 and Cl-37, in the ratio of 3:1.
on average, chlorine atoms have atomic mass of: [(35 * 3) + (37 * 1)] / 4
similarly, you can calculate the atomic...
one way to look at it involves electronegativity. For a bond to be ionic, difference in electronegativity should be greater than 1.7
electronegativity of N is 3.0, and that of hydrogen is 2.2
the difference is less than 1.7
electronegativity of barium is 0.89 and that of bromine is 2.96...
what IS the second experiment?? as far as i remember, the only way for graphite to become unusable is through oxidation; but here Cl- is preferentially discharged...so you wouldn't get oxygen... i believe you can still use the grphite electrode...
as long as Cl- is found in a greater...
all i know about alchemy is from paolo coelho's book, the alchemist. it's supposed to be an ancient art with two main objectives, still not yet accomplished. these are:
1) making the immortality potion
2) turning lead into gold
The unified atomic mass unit (u), or dalton (Da), is a small unit of mass used to express atomic and molecular masses. It is defined to be one twelfth of the mass of an unbound atom of the carbon-12 nuclide, at rest and in its ground state.
couldn't be of much greater help...
ethyl acetate can be synthesized from a simple esterification reaction. all you need is ethanol and ethanoic acid as reagents. Conc. sulphuric acid will be needed as catalyst(a few drops only). and yes, you will have to perform this under reflux while heating the mixture.
there is an ionic bonding when you consider Li+ and AlH4-
but, AlH4- is itself a covalent anion. there are 3 Al-H covalent bonds in this molecule... but AlH3 still has a vacant sub-orbital... coordinate covalent bond occurs... an H- bonds with the AlH3 forming AlH4-
maybe I'm wrong, but, when a substance dissolves, there is an energy change, e.g for NaCl to dissolve in water at rtp, the Delta H is +5kJ/mol
but for miscible substance I'm pretty sure there's no energy change... because the molecules only get between each other...
neutralisation involves rxn between H+ and OH-
whenever there is a rxn between an acid and a base, it is always a neutralisation one!
moreover, a weak acid will ionise completely during neutralisation.
as the OH- reacts with the H+ from the weak acid, the latter H+ decreases in...
methane consists of four bonded pairs, i.e 4 C-H bonds. So as to minimize repulsion, the molecule adopts a tetrahedral shape, hence bond angle becomes 109.5. with bond angle of 90, the molecule would not be very stable.