What is the empirical formula of the compound which has the following percentage composition carbon 80% hydrogen 20% if the molecular mass is 30?

CBSE 11-science - Chemistry

Sir Q.no 3

Asked by sahadipa1975 | 02 May, 2020, 08:53: AM

CBSE 11-science - Chemistry

ans with solutions

Asked by anilsolanki2060 | 22 Feb, 2020, 10:12: AM

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Text Solution

Solution : Calculation of empirical formula. <br> `|{:("Element","% age","Atomic","Constent","No of","Sample","Simplest whole"),(,," mass","in sample","moles"," ratio"," no. ratio"),(" C"," 80"," 12"," 80 g",(80)/(12)=6.66,(6.66)/(6.66)=1," 1"),(" H"," 20"," 1"," 20 g",(20)/(1)=20,(20)/(6.66)=3," 3"):}|` <br> `therefore` Empirical formula is `CH_(3)` <br> Calculation of molecular formula <br> Empirical formula mass `=12xx1+1xx3=15` <br> `n=("Molecular mass")/("Empirical formula mass")=(30)/(15)=2` <br> Molecular formula = Empirical formula `xx2` <br> `= CH_(3)xx2=C_(2)H_(6)` .