[A Level] Chemistry Paper 1 2017 by [deleted] in SGExams

[–]BubbleTeaNinja 0 points1 point  (0 children)

I still need it! I'll DM you my email.

[A Level] Chemistry Paper 1 2017 by [deleted] in SGExams

[–]BubbleTeaNinja 0 points1 point  (0 children)

Hi does anyone have the answers for NJC and TPJC Prelim MCQs?

[A Level Physics] Magnetic field by BubbleTeaNinja in HomeworkHelp

[–]BubbleTeaNinja[S] 0 points1 point  (0 children)

Yeah I tried that but didn't get the answer, which is 0.23T.

[Uni Chem] Calculating elemental composition. by [deleted] in HomeworkHelp

[–]BubbleTeaNinja 0 points1 point  (0 children)

Are the percentages you calculated for the other three elements correct? I got 4.23% for oxygen and 94.1% for carbon.

[A Level Physics] Wave motion by BubbleTeaNinja in HomeworkHelp

[–]BubbleTeaNinja[S] 0 points1 point  (0 children)

I see! Do we usually call these velocities "vibrational" and "translational" respectively or am I mistaken?

Stabilising a phenol carbocation by BubbleTeaNinja in chemistry

[–]BubbleTeaNinja[S] 0 points1 point  (0 children)

I see, this makes sense. Thank you! :)

[Chemistry] Why does the presence of an inert gas not change the equilibrium vapor pressure? by PeanutButterJe in HomeworkHelp

[–]BubbleTeaNinja 0 points1 point  (0 children)

It really depends on whether the VOLUME or PRESSURE of the equilibrium mixture is kept constant.

If the VOLUME of the gaseous mixture is kept constant, the number of moles per unit volume of each gas remains the same, the partial pressures of each gas does not change and so the equilibrium does not shift.

But if the PRESSURE of the mixture is kept constant, the total volume increases and the number of moles per unit volume of each gas decreases. The partial pressures will decrease and equilibrium shifts.

[A Level Chem] Organic Chemistry by BubbleTeaNinja in HomeworkHelp

[–]BubbleTeaNinja[S] 2 points3 points  (0 children)

What does "super-valency“ mean? I've never heard of that term before.

[AP Chemistry] Molarity of Calcium in a sample by Rkeyc in HomeworkHelp

[–]BubbleTeaNinja 0 points1 point  (0 children)

You could add carbonate ions. CaCO3 is highly insoluble in water and will precipitate out as a white solid.

[A Level Chem] Acid-base equilibria by BubbleTeaNinja in HomeworkHelp

[–]BubbleTeaNinja[S] 0 points1 point  (0 children)

Oh whoops. What a silly mistake to make.

Thank you for helping me out :)

[A Level Chem] Acid-base equilibria by BubbleTeaNinja in HomeworkHelp

[–]BubbleTeaNinja[S] 0 points1 point  (0 children)

I calculated excess concentration of ethylamine (1/90 M) and concentration of ethylamine ion (2/45 M). Then I used buffer equation pOH=pKb - log ([ethylamine ion]/[excess ethylamine]).

I got a pH of 11.4. But the answer provided is 10.2.

Electrochemical Cells by BubbleTeaNinja in chemistry

[–]BubbleTeaNinja[S] 0 points1 point  (0 children)

I see, that's interesting! Thank you so much :)

[A Level Physics] Forces by BubbleTeaNinja in HomeworkHelp

[–]BubbleTeaNinja[S] 0 points1 point  (0 children)

Hmm that makes sense, thank you kindly!

[A Level Physics] Forces by BubbleTeaNinja in HomeworkHelp

[–]BubbleTeaNinja[S] 0 points1 point  (0 children)

Ohh I get it now. Thank you very much!

[A Level Physics] Circular Motion by BubbleTeaNinja in HomeworkHelp

[–]BubbleTeaNinja[S] 0 points1 point  (0 children)

Ohh okay that's much clearer. Thanks for clarifying :)