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2 năm trước

Đốt cháy 14,2g hữu cơ A đc 28,6 g CO2;4,5g H2O và 5,3g Na2CO3.Biết A có 2 phân tử O2.Tìm Công thức phân tử

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Phan Huy Dương

2 năm trước

Đáp án:

Giải thích các bước giải:

Gọi CTPT là C$_{x}$H$_{y}$O$_{2}$Na$_{z}$

n$_{CO_{2}}$=28,6/44=0,65 (mol)

n$_{Na_{2}CO_{3}}$=5,3/106=0,05 (mol)=n$_{C}$

=>n$_{Na}$=0,1 (mol)

=>Tổng số mol C: n$_{C}$=0,65+0,05=0,7 (mol)

n$_{H_{2}O}$=4,5/18=0,25 (mol)

=>n$_{H}$=0,5 (mol)

Ta có: x:y:z=0,7:0,5:0,1=7:5:1

=>CTPT: C$_{7}$H$_{5}$O$_{2}$Na

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Đốt cháy 14,2g hữu cơ A đc 28,6 g CO2;4,5g H2O và 5,3g Na2CO3.Biết A có 2 phân tử O2.Tìm Công thức phân tử

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