Question

Giúp mình câu 14 với ạ

Answer 1

a)  C_M = \(\dfrac{n}{V}\Rightarrow n=C_M.V=0,9.2,5=2,25\left(mol\right)\)

b)                                 250 ml = 0,25 lit

     C_M = \(\dfrac{n}{V}\Rightarrow n=C_M.V=0,1.0,25=0,025\left(mol\right)\)

c) C⁰/₀ = \(\dfrac{m_{ct}.100}{m_{dd}}\Rightarrow m_{ct}=\dfrac{C.m_{dd}}{100}=\dfrac{4.50}{100}=2\left(g\right)\)

     n_MgCl2 = \(\dfrac{m_{MgCl2}}{M_{MgCl2}}=\dfrac{2}{95}=0,02\left(mol\right)\)

d) C⁰/₀ = \(\dfrac{m_{ct}.100}{m_{dd}}\Rightarrow m_{ct}=\dfrac{C.m_{dd}}{100}=\dfrac{15.200}{100}=30\left(g\right)\)

     n_KCl = \(\dfrac{m_{KCl}}{M_{KCl}}=\dfrac{30}{74,5}=0,4\left(mol\right)\)

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