Hay chon dap an diing.
7.46. Khir hoan toan m gam h6n hgp X g6m FeO va Fe203 bang H2 (t"), sau
phan ling thu dugc 9 gam H2O va 22,4 gam chat ran.
Thanh phin % theo mol ciia FeO trong h6n hgp X la bao nhieu ?
Ạ 66,67% ; B. 27,34% ; C. 54,12% ; D. 73,86%. C. 54,12% ; D. 73,86%. 124
47. rhdi lu6ng khf CO dir qua 6'ng sii dirng m gam h6n hgp g6m Fe304 va CuO nung nong, sau khi phan irng xay ra hoan toan thu dugc 2,32 gam CuO nung nong, sau khi phan irng xay ra hoan toan thu dugc 2,32 gam h6n hgp ran va chat khi X. Cho toan b6 X háp thu hét vao binh dirng dung dich Că0H)2 du, thu dugc 5 gam ket tuạ
Gia tri cua m la :
Ạ 3,22 gam; B. 3,12 gam; C. 4,31 gam; D. 3,64 gam. Hay chon dap s6' diing.
.48. Khir hoan toan 6,64 gam h6n hgp X g6m FeO va Fe203 c5n 2,24 lit khi
CO (dktc).Kh6'i lugng sat thu dugc la :
Ạ 5,12 gam; B. 4,86 gam ; C. 5,04 gam ; D. 5,86 gam. Hay chon dap s6' diing.
49. Ngam thanh kim loai M c6 khS'i lugng 50 gam trong dung dich HCl.
Sau phan irng thu dugc 336 ml H2 (dktc) va tháy khdi lugng thanh kim loai giam 1,68% so v6i ban dfiu:
M la kim loai :
A, Nh6m ; B. Kem ;
C. Magie ; D. Sat. ^
Hay chgn dap An diing.
50. Hoa tan 25 gam CUSO4.5 H 2 O vao nude cat, dugc 500 ml dung dich Ạ Danh gia gSn dung gia tri pH va ndng d6 mol ctia dung dich A : Danh gia gSn dung gia tri pH va ndng d6 mol ctia dung dich A :
Ạ pH < 7 va C M ( CUSO4 ) = 0,2M.
B. pH = 7 va C M ( CUSO4 ) = 0,2M.