Ответ:
21,64%
Объяснение:
дано
m(x) = 5
m(KNO3) = 15г
V(H2O) = 10
W - ?
n(H2O) = V(H2O) \ Vm
n(H2O) = 10\22.4 = 0.45
n(H2O) = m(H2O)/Mr(H2O)
m(H2O) = n(H2O) * Mr(H2O) = 0.45 * 18 = 8.1
W = n(x) \ m(KNO3) + m(H2O) * 100% = 5\15 + 8.1 * 100%= 5\23.1 * 100% = 21.64%