78____30=48
70____8=78
钩码总重/N
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
指针位置/cm
4.5
5.0
5.5
5.8
5. 8
①____ Na2S2O3+____HCl→____ NaCl+____S+____SO2↑+
____H2O
②____ Zn+____H++____NO3﹣→____ Zn2++____NH4++____H2O.