Bài 1:
\(CTTQ:ACO_3\\ \%m_{CO_3}=60\%\Rightarrow M_{ACO_3}=\dfrac{12+3.16}{60\%}=100\left(\dfrac{g}{mol}\right)\\ Mà:M_{ACO_3}=M_A+60\left(\dfrac{g}{mol}\right)\\ \Rightarrow M_A+60=100\\ \Leftrightarrow M_A=40\left(\dfrac{g}{mol}\right)\\ \Rightarrow A:Canxi\left(Ca=40\right)\)
Bài 2:
\(CTTQ:ASO_4\\ Vì:\dfrac{m_A}{m_{SO_4}}=\dfrac{2}{3}\\ \Leftrightarrow\dfrac{M_A}{32+4.16}=\dfrac{2}{3}\\ \Leftrightarrow M_A=\dfrac{2.\left(32+4.16\right)}{3}=64\left(\dfrac{g}{mol}\right)\\ \Rightarrow A:Đồng\left(Cu=64\right)\)
Bài 3:
\(CTTQ:AO_2\\n_X=\dfrac{4,48}{22,4}=0,2\left(mol\right)\\ n_{O_2}=\dfrac{8,96}{22,4}=0,4\left(mol\right)\\ m_X=m_{O_2}\\ \Leftrightarrow m_X=0,4.32=12,8\left(g\right)\\ M_X=\dfrac{12,8}{0,2}=64\left(\dfrac{g}{mol}\right)\\ Mà:M_X=M_{AO_2}=M_A+32\left(\dfrac{g}{mol}\right)\\ \Rightarrow M_A+32=64\\ \Leftrightarrow M_A=64-32=32\left(\dfrac{g}{mol}\right)\\ A:Lưu.huỳnh\left(S=32\right)\\ X:SO_2\)