Huong đn gidi
Theo bai ra: n^ci =a (mo!)
PTPU: Na + HCl > N a C l + - H , 2 ^ a a/2 (mol) 1 Na + H2O > NaOH + - H , 2 2 a/2 <-a/2(mol) ' Vay dung djch G c6 chu-a NaOH, NaCl. > /t
Cac chat tac dung duoc v6i dung dich G: Zn, AUOj, NaHSOj PTPl/:
Zn + 2NaOH + 2H20 >Na2 [Zn(OH)4]+H2 AI2O3 +2NaOH+3H20 >2Na[Al(OH)4] NaHS03 + NaOH > Na2S03 + H2O
'if
Chirang 7. C R O M - - D O l ^ G
M O T S»6 K I M M A I K H A C
Ị C R O M ^ , :Wr-I
1. Cáu tao cua crom
- Cr (Z = 24): [Ar] 3dHs' (cáu hinh ban bao hoa gáp phan lorp d).
- Trong hop chat, crom c6 s6' oxi hoa bifén d6i tir + 1 dS'n + 6. Ph6 bid'n hom ca la cac s6' oxi hoa +2, + 3 va + 6.
2. Tinh chat vat li
Crom la k i m loai nang (d = 7,2g/cm'), c6 mau trSng bac, kho nong chay, kho bay hoi, curng nhat trong s6' cac kim loaị
3. Tinh chat hoa hoc:
4Cr + 3 0 , — ^ 2Cr203 2Cr + 302 — ^ 2CrCl3
Cr + 2HC1 > CrCl, + HjT
Cr + H2SO4 (1) — ^ CrS04 + H ^ t '
Chu y: K i m loai crom b^n voi kh6ng khi, nu6c, dung dich HNO3 dac, ngu6i,
H2SO4 dac, nguoi la nhcf c6 16p mang oxit b^n bao ve (giong nh6m).
4. San xuat:
- Hop chat pho bién ciia crom la quang cromit FeỌ Cr203 (thucmg c6 iSn AUO, va Si02).
- Tiif quSng tach ra duoc Cr203, sau do di^u che crom bang phuong phap nhiet nh6m:
Cr203 + 2A1 — ^ 2Cr + AUOj.
11. MOT SO HOP CHAT CUA C R O M
1. Hofp chat crom (H) * ! i ; ! S >
ạ CrO, crom (II) oxit
- CrO la chat b6t, mau den, kh6ng tan va kh6ng tac dung voi H^Ọ - La oxit bazo va c6 tinh khir:
CrO + 2HC1 > Crạ + H2O
' ' i 4CrO + O2 — ^ 2Cr203 - D i l u ché: 2Cr(Hg) + Oj (Ue, > 2CrO + Hg (1)
Cty TNHH MTV PyVfTKhan^ Viet h. Cr(OH)2, crom(II) hidroxit.
- Cr(OH)2 la chat rSn, mau vang, kh6ng tan trong nudrc.
- La m6t bazo va c6 tinh khijr: ' '* Cr(OH)2 + H2SO4 (1) > CrS04 + H2O ' " '
4Cr(OH)2 + O2 + 2H2O > 4Cr(OH)3 \ .0
4Cr(OH)2 + O2 ——> ICr^Oj + 4H2O
- D i ^ u c h ^ .,i>,>r
CrCl2 + 2NaOH M " " ' ' . ' . ' > Cr(OH)4 +2Naa
c. Muoi crom (II) clorua, CrCl2
- CrQz khan la chat bot mau trSng, tan trong nuoc cho dung dich mau xanh lam.
- Co tfnh khir manh: ,
2CrCl2 + CI2 > 2CrCl3 ' > '
4CrCl2 + O2 + 4HC1 > 4CrCl3 + 2H2O
- Di^u che: Cr + 2HC1 CrCU +
2Cra3 + H2 — ^ CrClj + 2HC1 CrClj + [H] ) CrCl, + HCl
2. Hop chat crom (HI)
ạ Cr20}, crom(III) oxit
- La ch^t b6t mau luc t h i m (dang v6 djnh hinh, khi 6 dang tinh th^ c6 mau den anh kim), kh^ng tan trong nirdc.
- Cr,03 la m6t oxit lu6ng tinh:
Cr203 + 2 K 0 H — 2 K C r 0 2 + Hfi ,
kali cromit •1
CT2O3 + 6KHSO4 — ^ Cr2(S04)3 + 3K2SO4 + 3H2O
- Diiu ch6: KjCrjO, + S > Cr203 + K2SO4 I
(NH4)2Cr20, — ^ Cr.Oj + N2 + 4H2O
h. Cr(0H)3, crom(III) hidroxit
- La két tiia nh&y, mau luc nhat, khdng tan trong nu6c va c6 thanh pMn bián d6i (CrzOạxH.O).
- Co tinh chat luSng tinh:
Phchi loai va ;>liir(yii}i p/nip i>iiii nhanh ET Hda hoc 12 — Cii Ihinh Todn
Cr(OH)3 + NaOH,od, > Na[Cr(OH)4] ,0
- Kern ben nhiet: 2Cr(OH)3 ——> CrjOj + m.O
- Di^u Ché: Cr^* + SOH" > Cr(OH)3 i
c. Mud'i cram (III)
- VCra CO tfnh oxi hod, vira c6 tinh khir:
2CrCl3 + Zn ) 2CrCl2 + ZnCU ' ZCrClj + 3CU + 16NaOH > 2Na,Cr04 + 12NaCl + 8 H 2 O
2CrCl3 + 3 H A + lOKOH > 2K2Cr04 + 6KC1 + 8 H 2 O ,
- Phen crom - kali: K 2 S O 4. Cr,(S04)3. 24H3O
Co mau xanh tim, dung dé thu6c da, lam chat dm mau trong nganh nhu6m vaị 3. Hop chat crom (VI)
ạ CrO,, crom (VI) oxit
- La chat ran, mau do thSm, tan va tac dung \6i nirdc. - La oxit axit:
CrOj + H 2 O > W.CrÔ
Axit cromic 2Cr03 + H,0 > n.CuOj
^ Axit dicromic - Co tinh oxi hoa rat manh:
2Cr03 + 2NH, > Cv.O, + N , + SH^O 4Cr03 + 3C > 2Cr203 + SCO,
-Di^uché: K^Cr^O, + H 2 S O 4 ICvỌi +K,S04 + H20
h. Mud'i cromat va dicromat - Diu CO tinh oxi hoa manh: - Diu CO tinh oxi hoa manh:
K.Cr.Oy + S ' > Cr.Oj + K2SO4
K2Cr207+ 6FeS04 + 7 H 2 S O 4 _> Cr2(S04)3 + 3Fe2(S04)3 + K 2 S O 4 + 7 H, 0 K,Cr207 + 6 K I + 7 H 2 S O 4 > Cr2(S04)3 + 4K2SO4 + 3 ^ + IH.O
K.CrjO, + 14HC1 — > 3CUt + 2KC1 + 2CrCl3 + IH.O - Sir chuy^n hoa ISn nhau giffa mu6'i cromat va muói dicromat:
2CrÔ- + 2 H " < ^ 2HCr04 ^ Cr.Oi + H 2 O
mau vang mau da cam
can bang nay rát nhay cam vdri sir blén d6i pH cua dung djch: khi pH giam (m6i truong cang axit) can bang chuyén djch ve ban phai (tao ra dung djch mau da cam), khi pH tang (m6i trucmg cang ki^m) can bang chuy^n dich ve htn trai (tao ra dung
djch mau vapg). , - Phan umg tao thanh két tiia:
BaCr04i +2Ka
> A g j C r j O , ! +2KNO3
K2Cr04 + BaQj —
K2Cr207 + 2AgN03
K2Cr04 + 2AgN03 > Ag2Cr04 i + 2KNO3
n i t i t i t i t n t ±±± n t ±±± t t 1^ .>Q , • in.SAT 1. Cau tao
- Fe (Z = 26): [Ar] 3dHs^ hay [Ar]
- Trong hop chat sat c6 s6' oxi hoa + 2 hoac + 3: Fe-*: [Ar] 3d' hay [Ar]
Fé*: [Ar] 3d' hay [Ar]
2. Tinh chat vat h'
sat la kim loai nang, mku trang xam, deo, nhidt d6 nong chay, nhiet d6 s6i cao, dSn dien, dSn nhiet t6't, dac biet c6 tinh nhidm tir.
3. Tinh chat hoa hoc ,«'. Sat CO tinh khir trung binh, bi oxi hoa thanh ion Fe"* hoac Fé*.
fi
Fe + S — — > FeS (sat (II) sunfua).
0
—> FsjÔ (FcjOj. FeO, oxit sat tir).
-> 2FeCl3 (sat (III) clorua). 3Fe + 2O2 -
2Fe + 3 0 , —
Fe + 2HC1 > FeClj + H , ! r e + H2SO4 (/) > FeS04 + H , t
-> Fe2(S04)3 + 3SO2 + 6H2O
Fe(N03)3 + NOT + 2H2O
Fe + 6H2SO4 (dac)
Fe + 4HNO3 (/) —
Fe + CuS04«jd, > Cu i + FeS04. Fe + 3AgN03 (du) > Fe(N03)3 + 3Ag>l
3Fe + 4H20 ) Fe304 + 4H2t t°>57oOc
ifV
Fe + H, 0 > FeO + H j t
-> 4Fe(OH)3 (gi sat)
4Fc + 302(kk) + 6H20(kk) -
Chu v; - Axit H N O 3 dac, ngu6i; H2SO4 dac, ngu6i khong tac dung vdri Fe m^ in lam cho sat tr6 ntn thu d6ng.
Than log! v,) phifTfili; r'"''l' Ạ''"' nhunfi^nr-nM HOC iz - K^u 1 nam 1 oan
Fe + ZAgNOj > Fe(N03)2 + 2Ag4