6)
Ta có:
\({m_{dd}} = {m_{KCl}} + {m_{{H_2}O}} = 12 + 150 = 162{\text{ gam}} \to {\text{C}}{{\text{\% }}_{KCl}} = \frac{{12}}{{162}} = 7,4\% \)
7)
\({n_{NaOH}} = \frac{{16}}{{40}} = 0,4{\text{ mol;}}{{\text{V}}_{dd}} = 200ml = 0,2{\text{ lít}} \to {{\text{C}}_{M{\text{ NaOH}}}} = \frac{{0,4}}{{0,2}} = 2M\)
8)
1) \(2Na + S\xrightarrow{{{t^o}}}N{a_2}S\)
2) \(Mg + 2HCl\xrightarrow{{}}MgC{l_2} + {H_2}\)
3) \({N_2}{O_5} + {H_2}O\xrightarrow{{}}2HN{O_3}\)
4) \(CaC{l_2} + 2AgN{O_3}\xrightarrow{{}}Ca{(N{O_3})_2} + 2AgCl\)
5) \(2Mg + {O_2}\xrightarrow{{}}2MgO\)
6) \(2Al + F{e_2}{O_3}\xrightarrow{{{t^o}}}A{l_2}{O_3} + 2Fe\)