C a u 3. Dap an diing la B. Phuong trinh hoa hoc: Phuong trinh hoa hoc:
Fe + 2 H C l- ^ F e C l 2 + H 21 (1)
Cu + HCl: kh6ng phan ling (2) Theo (1): S6'mol Fe = sd'molHj = - = 0,12(mol). Theo (1): S6'mol Fe = sd'molHj = - = 0,12(mol).
22,4 = 0,12.56 = 6,72 (gam). = 0,12.56 = 6,72 (gam).
2. TL/ LUAN
a) Cac phuong trinh hoa hoc: ' '
Mg + 2HC1 -> MgCl^ + T ' (1)
MgC03+2HCl^MgCl2+C02T + H20 (2)
Khi bay ra la h6n hop H2 va CỘ ,1^,; ^
C02+Ca(OH)^^CaC03i + H20 (3)
b) Tinh kh6'i luomg m6i chat trong h6n hop A:
Theo (3): SÓ mol CO22 = so mol CaCO, = — - 0,15 (mol) ' 1 0 0
^ S6'mol H, = - ^ - 0 , 1 5 - 0 , 1 2 5 (mol). 22,4
Theo (1): So mol Mg = so mol H2 = 0,125 (mol).
-> m^^ =0,125.24 = 3 (gam).
m^gco, =^0.15-84 = 12,6 (gam). c) Theo(l)va (2): c) Theo(l)va (2):
So mol HCl = 2 (s6' mol H2 + so mol CO2) = 0,55 (mol). Thétich dung dich HCl 2M da dung la: Thétich dung dich HCl 2M da dung la:
y i , H c , = ^ = 0,275 (lit).
D e s o 2 . 2 1. TRAC NGHIEM KHACH QUAN
Cau 1. Dap an diing la Ạ
. Kh6'i luong NaCl trong 2 dung dich khi chua pha tr6n: m^,„ = 400.— + 1 0 0 . — = 72 +12,5 = 84,5 (gam) 100 100 ' V5 ^ m^,„ = 400.— + 1 0 0 . — = 72 +12,5 = 84,5 (gam) 100 100 ' V5 ^
^ C%(NaCl) = ^^'^ .100% = 16,9%. ^ ^ 400 + 100
Cau 2. Dap an dung la D.
Dat CTPT cua mu6'i ngam nude la NâCOj.xH^Ọ
T T i e o d ^ b a i : ^ ^ ^ = ^ ^ = ^ M^.^oo,.xH,o 106 + 18X 100 Giai phuong trinh dugc x = 10. Giai phuong trinh dugc x = 10.
Vay CTPT cua muC'i ngam nude la Na-jCOj-lOH^Ọ
Cau 3. Dap an diing la Ạ
Cac phuorng trinh hoa hoc:
Fe + HjSO, (/)FeSO, + t Zn + H,SO, (/) ^ ZnSO, + t Zn + H,SO, (/) ^ ZnSO, + t
BaCl^ + (/) -> BaSÔ i + 2Ha ,
cau 4. Dap an dung la B.
Phuong trinh hoa hoc:
2A1 + 3H,SO, Al, ( S O , + 3H21 (1)
Theo (1): S6' mol Al = 2 s6' mol Al^ (SO, \ 2 . — = 0,04 (mol). Kh6'i luong nh6m da phan ling: Kh6'i luong nh6m da phan ling:
m^, =0,04.27 = 1,08 (gam). Kh6'i luong la nhdm la: Kh6'i luong la nhdm la:
100
m = 1,08.—= 1,2 (gam).
C^u 5. Dap an diing la Ạ )
Cac phuong trinh hoa hoe:
Al + 3AgN03 ^ Al(NO3)3 + 3Ag 4 (1)