K 24.8/ 39 0.63 /0.63 1
Mn 34.7/ 55 0.63 /0.63 1
O 40.5 / 16 2.5 /0.63 4
KMnO4 Mr=39+55+16*4=158
<span><span>Al<span>(OH)</span>2</span> → <span>AlO</span>+<span>H2O
</span></span><span><span>Fe<span>(OH)</span>2</span> → <span>H2O</span>+<span>FeO
</span></span><span><span>2<span>Fe<span>(OH)</span>3</span></span> → <span>Fe2O3</span>+<span>3<span>H2<span>O
</span></span></span></span>
P2O5 + 3H2O=2H3PO4
m(в)=31 m(р)=69 w-?
n(P2O5)=m/M= 31г/ 142г/моль=0,22 моль
т.к. коэффициент перед P2O5 = 1, а перед H3PO4 = 2, то
n(H3PO4) = 0,22моль * 2 = 0,44моль
m(в-ва H3PO4)=n*m=0,44г*98г/моль=43,12г
W=m(в-ва)/m(р-ра)=43,12г/69г=0,6225=62,25%