Question

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Answer 1

Гидрооксид натрия - NaOH
M(NaOH)=23+16+1=40
w(Na)=23/40 * 100%=57.5%
w(O)=16/40 * 100%=40%
w(H)=1/40 *100=2.5%
Ответ: 3