Câu 4 :
\(m_{ct}=\dfrac{18,5.300}{100}=55,5\left(g\right)\)
\(n_{Ca\left(OH\right)2}=\dfrac{55,5}{74}=0,75\left(mol\right)\)
a) Pt : \(Ca\left(OH\right)_2+2HCl\rightarrow CaCl_2+2H_2O|\)
1 2 1 2
0,75 0,75
b) \(n_{CaCl2}=\dfrac{0,75.1}{1}=0,75\left(mol\right)\)
⇒ \(m_{CaCl2}=0,75.111=83,25\left(g\right)\)
c) \(m_{ddspu}=300+200=500\left(g\right)\)
\(C_{CaCl2}=\dfrac{83,25.100}{500}=16,65\)0/0
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