Câu 3:
a, %mCu = \(\dfrac{64.100\%}{188}\approx34\%\)
%mN = \(\dfrac{28.100\%}{188}\approx14,9\%\)
%mO = 100% - 34% - 14,9% = 51,1%
b, %mAl = \(\dfrac{54.100\%}{342}\approx15,8\%\)
%mS = \(\dfrac{96.100\%}{342}\approx28,07\%\)
%mO = 100% - 15,8% - 28,07% = 56,13%
Bài 3:
\(b\))
\(M_{Al_2\left(SO_4\right)_3}=27\times2+\left(32+16\times4\right)\times3=342\left(g/mol\right)\)
\(\%Al=\dfrac{27.2.100}{342}\approx15,78\%\)
\(\%S=\dfrac{32.3.100}{34}\approx28,07\%\)
\(\%O=100-15,78-28,07=56,15\%\)
Lm giúp e bài 2 câu b và bài 3 câu b ạ
