Chemistry Question Thread

Leeshi

Hey guyz,

So I need to put a caption under my assignment for safety and ethical considerations but I don't know what to put as my caption. Like I can't put in table 1: safety and ethical considerations. Anyone got ideas for me?

Thanks, Leeshi!

jinx_58

Leeshi
You could just caption it Table 1: Risk Assessment

-jinx_58

Billzene

Leeshi usually with risk assessments you need to give the experiment title as well

Leeshi

Billzene

My title is safety and ethical considerations. However, the teacher wanted a caption below so I have now named it 'Table 1: Risks and management assessment'. I probably didn't do very well 😅

-Leeshi

chemistry1111

how do we balance the positive ions migrating from anode to cathode in electroylsis. since there isnt a salt bridge
if someone could explain

jinx_58

chemistry1111
For galvanic cells, whichever undergoes reduction (i.e. gains electrons) is the cathode, and the one that undergoes oxidation is the anode (i.e. loses electrons).

I suggest you watch these vids, the lad has diagrams, and explains it really really well:
https://www.youtube.com/watch?v=teTkvUtW4SA
https://www.youtube.com/watch?v=7b34XYgADlM
https://www.youtube.com/watch?v=dRtSjJCKkIo

-jinx_58

PhytoPlankton

chemistry1111

I 100% agree with watching those videos @jinx_58 sent. Tyler really does have good visual diagrams. As for the salt bridge, electrolytic cells don't have a salt bridge because it isn't divided into two separate half-cells like galvanic cells. In electrolytic cells, both electrodes are in the same solution which is the electrolyte. The electrolyte facilitates the balance of the charge for electrolytic cells. The videos should explain what I am saying as well.

Hope that makes sense.

chemistry1111

does anyone have any good diagrams to explain galvanic cells because im abit confused on how it works. like how do we know which is anode and cathode based on equations

chemistry1111

thank you also in galvanic cells what does it mean when the switch is closed? would e0 value change if switch open

Billzene

chemistry1111 it means when the circuit is completed. When the switch is open, there’s a break in the circuit such that no current will flow, which means the E cell will be 0, once you complete it, your galvanic cell can now generate electrical energy. E° will still be a theoretical value

Manny

Hi, can someone pls answer this question for me.
Under acidic conditions, tin(II) reacts with hydrogen peroxide to produce tin(IV) and water. Write two half reactions, and hence the net ionic redox equation for this reaction.

Billzene

Manny straight away Sn2+ going to Sn4+ would be an oxidation half reaction given by Sn2+ —> Sn4+ + 2e-

Then H2O2 must be reduced to H2O. Since there’s an oxidation half reaction already, this reaction must be a reduction one. I’ll let you find the half equation with KOHeS and from there combine both half reactions

chemistry1111

does anyone have any hard questions on redox they can upload. thanks

chemistry1111

for the equation 2LIl(aq) + f2(g) —> 2LiF(aq) + I2(g)
i have identified that fluorine gas will be reduced and that I-1 will be oxidised. what would the reductant be? would it be 2LiI(aq) or do you write 2I^-1.

chemistry1111

for 2Cl- is the oxidation number -2 or -1 does the co-efficient in from of element affect oxidation numbers?

also 2nd question
why does pH increase in galvanic cell between H+/ h2 and cd2+ and cd electrode

chemistry1111

how do we know if graph shifts right or left for le Chateliers principle. and what does it mean shift

Billzene

chemistry1111 The term “shift” refers to the equilibrium position which you predict using LCP. It essentially means which side of the equilibrium system is favoured. Right shifts are seen on concentration-time graphs as increases in products and decreases in reactants after the system adjusts itself (compared to immediately after the change)

chemistry1111

does anyone have a good example or video to explain the ICE table for equilibrium calculations

BriMT

An important thing to remember about the ICE table is that you never NEED to use it, it's simply a neat/organised way of structuring your working out.

Here are your steps:

Draw out the table if you want to. I like to use a double line between reactants and products so it's easy to see what's on which side of the equation
Find out that change experienced by one of your species (e.g. Cl^- ) [change = equilibrium amount - initial amount]
Using the molar ratio from the balanced chemical equation, find the amount of change everything else experiences ( flip the sign ( + -> - or - -> +) for anything on the other side of the reaction equation.
Initial + change = equilibrium amount for each species

This explanation might not make much sense on it's own but if you read it along with an example it should help! There's a worked example here

chemistry1111

thanks

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