Ask me for chemistry help! (7 Viewers)

[Dylanamali]

Question: which of the following reagents would be most useful to separate barium ions from a solution which also contains magnesium ions?
a dilute h2so4
b potassium chloride solution
c sodium carbonate solution
d ammonia solution

A - dilute H2SO4 - precipitates out barium to form barium sulfate.

 

[yew]

correcto. i didnt get this one right lol. how are you fairing? im not as confident with the chemical monitoring, and batteries

 

[Dylanamali]

correcto. i didnt get this one right lol. how are you fairing? im not as confident with the chemical monitoring, and batteries

Umm not too bad hey, I'm really glad I started chem tutoring earlier in the year, its given me a lot of confidence. Batteries are a bit tricky, but in the end its just about knowing your equations and some general things regarding, cost, practicality, impact on society and environmental impact. But yeah, my main weakness is probably monitoring atm, and maybe some of the harder chemical calculations if they were to arise.

But yeah if you have any questions/need help with anything, I'll try my best to answer them.

 

[kr73114]

describe the correct technique for conducting titrations?

 

[kittyful]

When showing that an acid is a B-L acid do we always react it with H20 ?

 

[umz93]

Its the easiest way to show it

 

[zxreth]

When showing that an acid is a B-L acid do we always react it with H20 ?

yep

 

[Dylanamali]

When showing that an acid is a B-L acid do we always react it with H20 ?

Kitty - yes, well this is the most simplistic method of showing it. You can obviously do it through other reactions, but for simplicity's sake this is generally the best.

 

[Dylanamali]

describe the correct technique for conducting titrations?

In regards to the correct technique, there is a number of things you must consider. These include the preparation of a quality primary standard (e.g. knowing the properties of a good primary standard), the washing techniques and then actually conducting the titration.

When preparing a primary standard you must know its molecular formula, it must be easily weighed and transferred, it must not react with the air, it must be soluble etc.

The rinsing techniques: these include rinsing the burette and the pipette with the solutions they are to contain and rinsing everything else with distilled water. This is to minimise dilution which can provide inaccurate results. If you want further information on how this works, just ask and ill expand.

The actual titration: First a rough titre is done, to get an approximate end point, then three more titrations are done - an average is obtained.

 

[kittyful]

Kitty - yes, well this is the most simplistic method of showing it. You can obviously do it through other reactions, but for simplicity's sake this is generally the best.

even for B-L base too ?

 

[kittyful]

Is molarity the same as concentration ?

 

[Dylanamali]

even for B-L base too ?

Hmm this is a bit different.. it really depends on the question. But I understand what your saying.. e.g. for a base like NaOH you generally don't react it with water. It's ionisation is just NaOH -> Na + OH-.

But if it was just a very general question like write an equation showing a substance acting as bronsted lowry base. You could write virtually any neutralisation reaction as one of them is accepting a hydrogen ion. Even the ionisation of HCl in water could be used as in this case water is the B-L base.

 

[Dylanamali]

Is molarity the same as concentration ?

yup!

 

[zxreth]

can someone write up the conversions required for ppm calculations?

 

[Dylanamali]

can someone write up the conversions required for ppm calculations?

+1 i dont understand this aswell.

 

[kittyful]

How do you show that Al2O3 is amphoteric ?

 

[nightweaver066]

can someone write up the conversions required for ppm calculations?

As long as there is a 10^6 difference in the values, you can just divide the mass of the substance over the mass of solution.

You can use milligrams (1 x 10^-3) per kilogram (1x 10^3)

 

[Dylanamali]

How do you show that Al2O3 is amphoteric ?

with amphoteric substances you can react them with OH- and H3O+ e.g. in basic conditions (reacting with OH-) they will act as acids and in acidic conditions reacting with H3O+ they will act as bases.

 

[iAmCurium96]

HELP! i dont understand how to calculate oxidation numbers

 

[_deloso]

Umm not too bad hey, I'm really glad I started chem tutoring earlier in the year, its given me a lot of confidence. Batteries are a bit tricky, but in the end its just about knowing your equations and some general things regarding, cost, practicality, impact on society and environmental impact. But yeah, my main weakness is probably monitoring atm, and maybe some of the harder chemical calculations if they were to arise.

But yeah if you have any questions/need help with anything, I'll try my best to answer them.

Do you know your concepts well and understand it? or are you rote learning it? cos I know my classmates who does chem tutoring and they are unable to answer the questions where you need to conceptualise. mostly band 5/6 questions.

and guys I'm more than happy to help as well!!! message me if you need any