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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: gurminder89 on March 19, 2007, 11:16:02 PM

Title: NEED HELPPPPPPPPPPPPPPPPPPP
Post by: gurminder89 on March 19, 2007, 11:16:02 PM

a compound with an empirical formula of SIH₄ has a molar mass of 96.g/mole.determine the molecular formula  ??? ??? ??? ??? ??? ??? ???

Title: Re: NEED HELPPPPPPPPPPPPPPPPPPP
Post by: Yggdrasil on March 19, 2007, 11:44:59 PM

If the empirical formula is SIH₄ then the ratio of S:I:H in the compound is 1:1:4.  So, the compound will have a molecular formula of S_nI_nH_4n.  Find the molecular weight of this compound in terms of n and then set it equal to 96g/mol.  Solve for n and then you have your molecular formula.

Title: Re: NEED HELPPPPPPPPPPPPPPPPPPP
Post by: madscientist on March 20, 2007, 02:35:22 AM

You sure the empirical formula isn't SiH₄? Because the minimum molecular weight for SIH₄ (n=1) is 163.002 g/mol.  Im fairly sure it is SiH4, with the ratio being  Si:H = 1:4