Question

100ml dd H3PO4 2M và 150ml dd NaOH 2,5M. Tính nồng độ mol muối

Answer 1

\(n_{H_3PO_4}=2.0,1=0,2\left(mol\right)\)

\(n_{NaOH}=2,5.0,15=0,375\left(mol\right)\)

PTHH: NaOH + H₃PO₄ --> NaH₂PO₄ + H₂O

_______0,2<----0,2--------->0,2

NaH₂PO₄ + NaOH --> Na₂HPO₄ + H₂O

0,175<-----0,175------>0,175

=> n_NaH2PO4 = 0,025 (mol)

=> n_Na2HPO4 = 0,175 (mol)

=> \(\left\{{}\begin{matrix}C_{M\left(Na_2HPO_4\right)}=\dfrac{0,175}{0,1+0,15}=0,7M\\C_{M\left(NaH_2PO_4\right)}=\dfrac{0,025}{0,1+0,25}=0,1M\end{matrix}\right.\)