Câu 1:
a,
$n_C=n_{CO_2}=\dfrac{1,32}{44}=0,03(mol)$
$n_H=2n_{H_2O}=\dfrac{0,54}{18}.2=0,06(mol)$
$\to n_O=\dfrac{0,9-0,03.12-0,06.1}{16}=0,03(mol)$
$n_C: n_H: n_O=0,03:0,06:0,03=1:2:1$
$\to$ CTĐGN: $CH_2O$
b,
Đặt CTTQ: $(CH_2O)_n$
$\to (12+1.2+16)n=180$
$\to n=6$
Vậy cacbohidrat là $C_6H_{12}O_6$
Câu 2:
$n_C=n_{CO_2}=\dfrac{0,792}{44}=0,018(mol)$
$n_H=2n_{H_2O}=\dfrac{0,297}{18}.2=0,033(mol)$
$\to n_O=\dfrac{0,513-0,018.12-0,033.1}{16}=0,0165(mol)$
$n_C: n_H: n_O=0,018:0,033:0,0165=12:22:11$
$\to$ CTĐGN: $C_{12}H_{22}O_{11}$
Đặt CTTQ: $(C_{12}H_{22}O_{11})_n$
$\to (12.12+1.22+11.16)n=342$
$\to n=1$
Vậy cacbohidrat là $C_{12}H_{22}O_{11}$
Câu 3:
$n_C=n_{CO_2}=\dfrac{13,44}{22,4}=0,6(mol)$
$n_H=2n_{H_2O}=\dfrac{9}{18}.2=1(mol)$
$\to n_O=\dfrac{16,2-0,6.12-1.1}{16}=0,5(mol)$
$n_C: n_H: n_O=0,6:1:0,5=6:10:5$
$\to$ CTĐGN: $C_6H_{10}O_5$
$X$ là tinh bột hoặc xenlulozơ