\(n_{H_2}=\dfrac{0,2479}{24,79}=0,01\left(mol\right)\)
BT e có: 2nM = 2nH2
⇒ nM = 0,01 (mol)
\(\Rightarrow M_M=\dfrac{1,37}{0,01}=137\left(g/mol\right)\)
→ M là Ba.
BTNT Ba: nBa(OH)2 = nBa = 0,01 (mol)
\(\Rightarrow a=C_{M_{Ba\left(OH\right)_2}}=\dfrac{0,01}{0,5}=0,02\left(M\right)\)