Răspuns:
50 mL sol. HNO₃
Explicație:
1. Calculăm masa de NaOH.
[tex]\rm m_{NaOH}=m_d[/tex]
[tex]\rm m_d=\dfrac{m_{solvent}}{5}\implies m_{solvent}=5m_d[/tex]
[tex]\rm m_s=m_d+m_{solvent}[/tex]
[tex]\rm 24g=m_d+5m_d[/tex]
[tex]\rm 24g=6m_d\implies m_d=24g:6=\bf4g[/tex]
2. Calculăm numărul de mol de HNO₃ care a neutralizat cele 4g de NaOH.
[tex]\rm M_{NaOH}=40\dfrac{g}{mol}[/tex]
4g x
NaOH + HNO₃ → NaNO₃ + H₂O
40g 1 mol
x = 4 / 40 = 0,1 mol HNO₃
3. Calculăm volumul soluției de HNO₃ de concentrație 2M = 2 mol/L.
[tex]\rm c_M=\dfrac{n}{V_s}\implies V_s=\dfrac{n}{c_M}[/tex]
[tex]\rm V_s=\dfrac{0,1\sout{mol}}{2\dfrac{\sout{mol}}{L}}=\bf0,05L[/tex]
-Mihai
