C% của dd NaOH:
\(\dfrac{72.100}{200}=36\%\)
Ta co pthh
Na2O+H2O\(\rightarrow\)2NaOH
Theo de bai ta co
C% cua NaOH=\(\dfrac{mct}{mdd}.100\%=\dfrac{72}{200}.100\%=36\%\)
C%ddNaOH = \(\dfrac{mNaOH}{m\text{dd}NaOH}\)x100%=\(\dfrac{72}{200}\)x100%=36%
C%ddNaOH=\(\dfrac{mct.100}{mdd}\)\(\underrightarrow{ }\)C%ddNaOH=\(\dfrac{72.100}{200}\)=36%