Cho a gam K2Cr2O7 vao dung dich HCl dac, du thay thoat ra khi Cl2. Khi Cl2 thoat ra phan ung vua du voi 13,0 gam Cr. Gia tri cua a la:
A. 44,10 B.39,69 C.36,75 D.51,45
Cho a gam K2Cr2O7 vao dung dich HCl dac, du thay thoat ra khi Cl2. Khi Cl2 thoat ra phan ung vua du voi 13,0 gam Cr. Gia tri cua a la:
A. 44,10 B.39,69 C.36,75 D.51,45
K2Cr2O7 + 14HCl→ 3Cl2+2KCl+2CrCl3+7H2O
0,125 ← 0,375 (mol)
2Cr +3Cl2➝2CrCl3
0,25→0,375 (mol)
a= 0,125.294=36,75g