The empirical formula is M2O3, if 16.0g of the metal oxide was reduced to 11.2g of metal, find the relative atomic mass of M.
Alrighty then, I thought, easy-peasy! First, the reaction formula, which is a reduction reaction, so oxygen is taken away, therefore...
16 (mass of M2O3) /2x (RAM of M) + (16x3) (RMM of 3 O) = y ------- 1
Ohkay! Following that, for the other side of the equation :
11.2 (mass of M) / x (RAM of M) = 2y ------- 2
So therefore, substitute 1 into 2, and you get :
11.2 / x = 16 / x + 24
Cross-multiply, solve the equation, and you will get x=56! Easy! Okay, then, I thought that was easy, but that wasn't anything yet... What follows is the heavily edited version of our 3-way conversation, but nothing I changed will affect the flow... Mostly it's more about taking away unneccessary 'hahaha's, 'lolz's and the like. Oh man.... (C=Cass, S=Symeon, M=Me)
C:thats the question
S:M2O3 is a batch in IMU ler
M:bosan dy lar dat joke
M:hahaha, faham lar (she's still blur as always...)
C:how to do?
S:i got 74.7 (??? What???) hahahaha sounds like wrong
C:yeah, it is. answer given is 56 larrr
M:i got 56 (mwahahahahaahaha)
S:how come i get 74.7?
M:u lar, cacat. (lolz) ok, listen carefully
C:hahaha i noe u very good lar (cheh, I take that as a compliment!)
M:reduced means take away O, so the reaction is like this (shows reaction formula)
(at this point Cass takes off to get paper, leaving me gesturing to thin air. HAIH!)
M:wanna explain 2 u... wahhhhh
C:get paper lar, ok go on
M:understand so far?
C:yupp, got that
M:ohkay, (explains the premise and the following equation) faham?
C:... (she blurred out, again!)
M:blur liao izzit? don understand mus say... read slowly again
C: yeah don get it, wait. why 16/2m?
M:haiya, how do u get no of moles?
S:?!?!?!?!?! apa ini? 4.8g of O, divide 3, eh, divide 16, get 0.3. 3 mol of O = 0.3, 1 mole of O = .01
S:11.2/x = 0.1, x=112, but got 2M, so 1M=56 (WHAAATTTT? Don't ask me, I have no idea...)
M: (anyway) slow lar symeon
M:yeah lar, i explain 2 her 1st, den u explain
S:but my way wont full marks (HUH? It will be a wonder if you get ANY!)
M:yeah lar, dats y im explaining. blekz. okay, faham?
C:ummm, i stil don get it (*FAINT*) lol.. no
S:kenot lar, MSN very hard 2 explain (OBVIOUSLY!)
M:okay, step by step (explains the whole 1st equation)
C:(when I came to the mass) mass of wat (wahdoi!)
S:hehehe, matt, angina dy (Errrrr, don't ask me to explain that, ask HIM!)
M:(*sigh*) oxide lor, Symeon don say dy lar, pek chek dy. hahaha, no lar, stil can tahan. understand? so RFM? (I realized that maybe she dosen't understand) or RMM watever...
C:48 + 2X?
M:ha, pandai pun, so continue on.... ganti inside the info wat u get?
S:MOLES!!! (wahdoi Symeon!)
M:simplified dy lar Symeon
S:yeah ok, yayayaya (haih)
M:okay, so if u use y moles at d beginning, in d end?
C:huh? (WAAAHHHHH, wanted to cry dy)
S:hehehe, streptokinase ready. wait call OT 1st, ha OT available, scrub nurse on... can boh cass?
C:no (heartache, heartache!)
S:want my unprofessional explaination
M:no marks 1 lar (hehehehehe) okay go again. (explains again....)
C:oh wait let me try... (tick tock tick tock)
M:......... (maybe I have to break this up if I do post this...)
Ohkay, Part 1 over! Lolz... You can see me, the teacher having a LOT of headaches because of this student... Haih... Kesian juga those teachers.... Hahahahaa.... Ok, coming back with the second part after this short break!
Can't wait? Here's Part 2!
Teaching? Me? (Part 2)