Author Topic: chem help......hey some question please explain answer  (Read 643 times)

Offline cashem'up

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chem help......hey some question please explain answer
« on: February 25, 2010, 06:48:03 pm »
13 Which of the following oxides is unlikely to dissolve in aqueous sodium hydroxide?
A Al 2O3 B MgO C SO2 D SiO2

ANS is B

With this i am always confused by one thing ,as you go down the group the no. a of shells increase and charge density decreases , this would mean the distortion due to polarization decreases and thus thermal stability increases as bonds become harder to break , then how come when we dissolve hydroxides , down the group the solubility increases , bcos shouldnt be harder to break the bonds as you go down.........


Offline Phosu

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Re: chem help......hey some question please explain answer
« Reply #1 on: February 26, 2010, 08:38:11 am »
well i dont get wat you said but heres what i think, MgO is a base, SO2  is an acidic gas, Al2O3 and SiO2 are amphoteric, thus except for MgO the rest will dissolve causing a neutralization reaction

nid404

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Re: chem help......hey some question please explain answer
« Reply #2 on: February 26, 2010, 09:58:01 am »
well i dont get wat you said but heres what i think, MgO is a base, SO2  is an acidic gas, Al2O3 and SiO2 are amphoteric, thus except for MgO the rest will dissolve causing a neutralization reaction

yup that right