Tính thành phần % về khối lượng của các nguyên tố có trong hợp chất sau: CuO, P2O5, H2SO4, Al2(SO4)3, NH4NO3, Ca3(PO4)2
2 câu trả lời
$M_{CuO}=64+16=80(g/mol)$
$\%m_{Cu}=\dfrac{64}{80}.100\%=80\%$
$\%m_O=100-80=20\%$
$M_{P_2O_5}=31.2+16.5=142(g/mol)$
$\%m_P=\dfrac{31.2}{142}.100\%\approx 43,66\%$
$\%m_O=100-43,66=56,34\%$
$M_{H_2SO_4}=2+32+16.4=98(g/mol)$
$\%m_H=\dfrac{2}{98}.100\%\approx 2,04\%$
$\%m_S=\dfrac{32}{98}.100\%\approx 32,65\%$
$\%m_O=100-2,04-32,65=65,31\%$
$M_{Al_2(SO_4)_3}=27.2+(32+16.4).3=342(g/mol)$
$\%m_{Al}=\dfrac{27.2}{342}.100\%\approx 15,79\%$
$\%m_S=\dfrac{32.3}{342}.100\%\approx 28,07\%$
$\%m_O=100-15,79-28,07=56,14\%$
$M_{NH_4NO_3}=14.2+4+16.3=80(g/mol)$
$\%m_N=\dfrac{14.2}{80}.100\%=35\%$
$\%m_H=\dfrac{4}{80}.100\%=5\%$
$\%m_O=100-35-5=60\%$
$M_{Ca_3(PO_4)_2}=40.3+(31+16.4).2=310(g/mol)$
$\%m_{Ca}=\dfrac{40.3}{310}.100\%\approx 38,71\%$
$\%m_P=\dfrac{31.2}{310}.100\%=20\%$
$\%m_O=100-20-38,71=41,29\%$
$\text{Đáp án+Giải thích các bước giải:}$
$\text{MCuO=64+16= 80 g/mol}$
$\text{%mCu=$\dfrac{64}{80}$×100= 80%}$
$\text{%mO=$\dfrac{16}{80}$×100= 20%}$
$\text{MP2O5=31×2+16×5= 142 g/mol}$
$\text{%mP=$\dfrac{31×2}{142}$×100= 43,66%}$
$\text{%mO=$\dfrac{16×5}{142}$×100= 56,34%}$
$\text{MH2SO4=2+32+16×4= 98 g/mol}$
$\text{%mH=$\dfrac{1×2}{98}$×100= 2,04%}$
$\text{%mO=$\dfrac{16×4}{98}$×100= 65,31%}$
$\text{%mS=$\dfrac{32}{98}$×100= 32,65%}$
$\text{MAl2(SO4)3=27×2+32×3+16×4×3= 342 g/mol}$
$\text{%mAl=$\dfrac{27×2}{342}$×100= 15,79%}$
$\text{%mO=$\dfrac{16×4×3}{342}$×100= 56,14%}$
$\text{%mS=$\dfrac{32×3}{342}$×100= 67,61%}$
$\text{MNH4NO3=14+1×4+14+16×3= 77 g/mol}$
$\text{%mN=$\dfrac{14}{77}$×100= 18,18%}$
$\text{%mO=$\dfrac{16×3}{77}$×100= 62,34%}$
$\text{%mN=$\dfrac{14}{77}$×100= 18,18%}$
$\text{%mH=$\dfrac{1}{77}$×100= 1,30%}$
$\text{MCa3(P2O4)2=40×3+31×2+16×4×2= 310 g/mol}$
$\text{%mP=$\dfrac{31×2}{310}$×100= 20%}$
$\text{%mO=$\dfrac{16×4×2}{310}$×100= 41,29%}$
$\text{%mCa=$\dfrac{40×3}{310}$×100= 38,71%}$