Question

a) Có bao nhiêu gam natri trong 60g xút ăn da NaOH? 26,5 natri cacbonat Na₂CO₃?

b) tính lượng vôi sống CaO mà trong đó chứa:

1) 0,4g canxi 2) 20kg canxi

Answer 1

a)

\(n_{NaOH}=\frac{60}{24+17}=1,5\left(mol\right)\Rightarrow n_{Na}=n_{NaOH}=1,5\left(mol\right)\Rightarrow m_{Na}=23\times1,5=34,5\left(g\right)\)

\(n_{Na_2CO_3}=\frac{26,5}{46+60}=0,25\left(mol\right)\Rightarrow n_{Na}=2n_{Na_2CO_3}=0,5\left(mol\right)\Rightarrow m_{Na}=0,5\times23=11,5\left(g\right)\)

Answer 2

b)

1.\(n_{Ca}=\frac{0,4}{40}=0,01\left(mol\right)\Rightarrow n_{CaO}=n_{Ca}=0,01\left(mol\right)\Rightarrow m_{CaO}=0,01\times56=0,56\left(g\right)\)2.

\(n_{Ca}=\frac{20}{40}=0,5\left(mol\right)\Rightarrow n_{CaO}=n_{Ca}=0,5\left(mol\right)\Rightarrow m_{CaO}=0,5\times56=28\left(kg\right)\)