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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: matt123 on March 18, 2011, 04:43:25 pm

Title: MATHS ( SIG FIG ) AND ALSO CHEM QUESTION PART 2 .. PLEASE HELP
Post by: matt123 on March 18, 2011, 04:43:25 pm
okkk guys
so i got a few questions from the book that im stuck on ..

first one is a maths one

14.00/37.800 X 6.022 = TO THE right amount of sig figs !!
the options are

2.23037
2.23
2.2
2.230
2.2304

i think its 2.230

can some 1 please help me?

2 also
chem questions

aluminium ion al3+ has ..
i said ... 13 protons and 10 electrons .. is this correct?

also 3
gadolinium oxide contains 86.76 mass % GD. .. determine its empirical forumla ... i said Gd203... is this correct ?



also 4 is the correct name for N203 = dinitrogen trioxide?

also 5
 
which of the following is most likely to form when an S atom forms an ion
S6+
S2-
S4+
S4-
none of the above
and i said ... S2- .. is this correct?


please help me !!

many many thanks in advanced guys.

Title: Re: MATHS ( SIG FIG ) AND ALSO CHEM QUESTION PART 2 .. PLEASE HELP
Post by: jane1234 on March 18, 2011, 04:55:19 pm
Quote
14.00/37.800 X 6.022 = TO THE right amount of sig figs !!
the options are

2.23037
2.23
2.2
2.230
2.2304

i think its 2.230

can some 1 please help me?

Think you're right ... generally it is the least number of sig figures given in the question...
Title: Re: MATHS ( SIG FIG ) AND ALSO CHEM QUESTION PART 2 .. PLEASE HELP
Post by: matt123 on March 18, 2011, 07:15:37 pm
hmmm ok i hope so

some one pleasseee help me with the rest!
ahah
Title: Re: MATHS ( SIG FIG ) AND ALSO CHEM QUESTION PART 2 .. PLEASE HELP
Post by: pi on March 18, 2011, 07:22:21 pm
Quote
also 5
 
which of the following is most likely to form when an S atom forms an ion
S6+
S2-
S4+
S4-
none of the above
and i said ... S2- .. is this correct?
Correct, sulfide ions are S2-


Quote
2 also
chem questions

aluminium ion al3+ has ..
i said ... 13 protons and 10 electrons .. is this correct?
Correct


Quote
also 4 is the correct name for N203 = dinitrogen trioxide?
Correct


Quote
also 3
gadolinium oxide contains 86.76 mass % GD. .. determine its empirical forumla ... i said Gd203... is this correct ?
Correct