Chemistry Forum

thank you so much, you are a genius

I understood my mistake. So does that mean that whenever you take an aliquot of a solution, the number of moles will change and the concentration will remain constant? Besides that, as it evaporated, the number of moles remains constant, only what will change and the volume and concentration?

I had started the account by calculating the initial number of moles and assuming that even transferring only 100 ml, the number of moles would remain constant, only the concentration and volume would change. Is that right? so, initially we have: 0.0025 mol with 100ml the concentration is 0.025 and ...

A laboratory technician uses a volumetric flask to prepare 500 mL of a 0.005 M solution of KOH (aq). Subsequently, transfer 100.0 mL of the prepared solution to a flask. Forgetting to cap the bottle, the technician Leave the solution in an open container for several days before use. During this time...

Cl2

At which of the carbons of the compound below is the bond breaking most likely to occur? Please answer explaining the factors that influence this breakage, namely: number of atoms available; positioning and electron density

* CH3-CH2-CH3 + Cl -->

I think you dont understand the System. Of course is nitrogen still 3valent. The calculation is based on the bond. The Nitrogen bond to 2 CH3- and one bond to the other nitrogen. On the other side there 2 bonds to H and one to the first nitrogen. But this has nothing to do with the calculation. A -...

Start in this way. Let say you have ammonia NH3 then N is calculated 3*(+1) H = 3 what means 3 positiv charges have to compensate with 3 negative charges, so the charge is -3 for N. Now we look on hydrazin H2NNH2. We have one N-N bond what gives 0. So we have to check the only NH2 . Like above we 2...

You talking about oxidationnumber of the elements. H is +1 in most compounds , -1 in hydrides like NaH. C can be from +4 to -4 depending on partner. Elektronegativity number. N can be -3 to + 5 depending on partner Bonds between the same element here N is 0. [(CH3)2N-NH2] H is + 1 C -2 calculated a...

Yes there is a law Acidic conditions Reduction: if oxygen is in the reaction, then H+ is added on reactant side and water is obtained on product side Oxidation is vise versa Alkaline conditions Reduction: if oxygen is in the reaction, then water is added on reactant side and OH- is obtained on prod...

Please use english. How do you determine o nox of each element of this compost? But its not understandable what is meant. Can you described more in detail. Sorry, given this compound: 1,1-dimethylhydrazine, the request is to determine the nox of each element in it. Example: H = +1. My difficulty is...

Como determina o nox de cada elemento deste composto?

[(CH3)2N-NH2]

Redox pair MnO4-/Mn 2+ and H2O2/ O2 Reduction in acidic conditions MnO4- + 8 H+ + 5 e- => Mn 2+ + 4 H2O Oxidation H2O2 => 2 H+ + 2 e- + O2 Multiplikation of equations 2 MnO4- + 16 H+ + 10 e- => 2 Mn 2+ + 8 H2O 5 H2O2 => 10 H+ + 10 e- + 5 O2 Addition 2 MnO4- + 6H+ + 5 H2O2 => 2 Mn 2+ + 8 H2O + 5 O2 ...

Muito obrigada, entendi

How is the balance of the equation that has this special case of hydrogen peroxide

Como é o balanceamento dessa equação que tem esse caso especial da água oxigenada

KMnO4 + H2O2 + H2SO4 = K2SO4 + MnSO4 + H2O + O2