,urhadf; fzpj;jy;fs;

gy;Nju;T tpdhf;fs;

(2019/old & new /mcq 04)

(2019/old & new /mcq 19)

(2018/mcq/06)

(2018/mcq/19)

5) jpzpTg;gb 75% KHCO3 If; nfhz;l KHCO3, CaCO3 jpz;kf;fyitapdJ 0.8g Kw;whfg;gpupAk;

tiu caH ntg;gepiyf;F ntg;gg;gLj;jp epak ntg;g mKf;f epge;jidapy; FspHtpf;Fk; NghJ

ngwg;gLk; CO2 thAtpd; fdtsT ( K – 39, Ca – 40, C – 12, O – 16, H – 1)

(1) 0.1792 dm3 (2) 0.0672 dm3 (3) 0.112 dm3 (4) 0.0448 dm3 (5) 0.168 dm3

(2017/mcq 08)

1)

2)

3)

4)

6) fe;jfj;ij fiue;j epiyapy; nfhz;Ls;s C7H16 khjpupapd; 13.2g MdJ 1.3mol O2 cld; %ba

ghj;jpunkhd;wpy; fyf;fg;gl;L Kw;whf jfdkhf;fg;gl;L FspHtpf;fg;gl;lJ. ,jd; NghJ 14.4g ePH

ngwg;gl;lJ. ,q;F ngwg;gl;l thA tpisT vJTk; ePupy; fiuatpy;iy vdf; nfhz;L jfd

,Wjpapy; fhzg;gLk; O2, CO2, SO2 thAf;fspd; nkhj;j %y;fs;

(1) 0.75 (2) 0.8 (3) 0.85 (4) 0.9 (5) 0.95

(2017/mcq 13)

7) A vd;Dk; NrHitahdJ Brypd; jfdj;jpd; %yk; cUthFk; Gifapd; msitf;

Fiwg;gjw;fhf NrHf;fg;gLk; vupnghUl; NrHkhdkhFk;.

A ,d; 1 %ypid Kw;whf jfdkilar; nra;tjw;F Njitahd xl;rprd; thAtpd; %y;

msT

(1)8 (2) 8.5 (3) 9 (4) 9.5 (5) 10

(2016/mcq16)

;fl;Liu tpdhf;fs;

01)

CuS, FeS, ZnS, rlj;Jt khR Mfpatw;iw nfhz;l jpz;kf; fyitnahd;wpd; 4.0 g MdJ kpif 0.3

mol dm-3 mkpy KMnO4 fiurypd; 200 cm3 cld; gupfupf;fg;gl;lJ. ntspNaWk; SO2 thAit Kw;whf

mfw;Wtjw;fhf fiury; ntg;gg;gLj;jg;gl;lJ. mj;Jld; tpisthFk; Mn2+ ck; tpNrl nrad;Kiw

xd;wpd; %yk; mfw;wg;gl;L ngwg;gl;l tpisTf; fiury; Z gpd;tUk; eilKiwfSf;F

cl;gLj;jg;gl;lJ.

eilKiw : 01

fiury; Z ,d; 100 cm3 vLf;fg;gl;L 1 mol dm-3 Fe2+(aq) cld; epakpf;fg;gl;l NghJ mjd; 25

cm3Njitg;gl;lJ.

eilKiw : 02 fiury; Z ,d; gpwpnjhU 50 cm3 vLf;fg;gl;L kpif NH3 fiury; ,lg;gl;L

ngwg;gLk; tPo;gbT tbj;J khwhj;jpzpT ngwg;gLk; tiu td;ikahf ntg;gg;gLj;jg;gl;l NghJ

0.16 g jpz;k kPjp ngwg;gl;lJ.

eilKiw : 03 eilKiw 02 ,ypUe;J ngw;w tbjputj;jpw;F kpifasT Ijhd mkpyk;

Nru;f;fg;gl;L mNkhdpah KOtJk; eLepiyahf;fg;gl;l gpd;du; kpifahf KI(aq) Nru;f;fg;gl;lJ.

tpLtpf;fg;gl;l I2(aq) I epakpf;f 0.2 mol dm-3 Na2S2O3 fiurypd; 30.0 cm3 Njitg;gl;lJ.

1. eilngWk; jhf;fq;fSf;fhd rkg;gLj;jpa rkd;ghLfis jUf.

2. khjpupapYs;s CuS, FeS, ZnS ,d; jpzpTr; rjtPjq;fisf; fzpf;f.

(Cu- 63.5, Fe- 56, Zn- 65, S- 32, O- 16, H- 1)

(2019/B/8/c)

(2018/B/8/c)

02)

03) ePupd; td;ikahdJ ePupy; Ca2+, Mg2+ cg;Gf;fs; fiue;jpUg;gjdhy; vOfpd;wJ. ePupd;

epiyapy; td;ikahdJ Ca2+, Mg2+ ,d; ,UfhgNdw;Wf;fshYk;> epiyahd td;ikahdJ ,t;

mad;fspd; FNshiul;L> ry;Ngw;W cg;Gf;fs; ,Ug;gjdhYk; Vw;gLfpwJ. XH ePHf;fiurypy; cs;s

Ca2+, Mg2+ mad;fspd; nkhj;j msit Jzptjpy; EDTA[H2Y2-] cld; epakpj;jy; xU

nghUj;jkhd eltbf;ifahFk;. ,e;epakpg;gpd; Jy;ypakhd KbTepiyia fz;lwptjw;F

Erichrome black T (In) vd;Dk; fhl;b gad;gLj;jg;gLfpwJ. ,f;fiurypd; pH 10 I tpl caHthf

cs;sNghJ fhl;bahdJ cNyhf maDld; NrHe;J itd; rptg;G [wine red] epwkhf fhzg;gLk;

mNjNtis ,f;fhl;bahdJ H+ cld; NrHe;J RahjPdkhf ,Uf;Fkhapd; ePyepwkhfTk;

fhzg;gLk;.

MIn- + H2Y2-→ HIn2- + MY2- +H+

(Wine red) (Blue)

(,q;F M MdJ Ca2+ my;yJ Mg2+ IAk; In vd;gJ fhl;biaAk; Fwpf;Fk;)

khztd; xUtd; ePHkhjpupapy; cs;s epiyahd td;ikia Jzpa gpd;tUk; eilKiwfis

gpd;gw;wpdhd;.

eilKiw I:- td;ePH khjpupapd; 50cm3MdJ epakpg;G FLitapDs; vLf;fg;gl;L pH I 10

,y; epiyepWj;Jtjw;fhf NH4Cl/ NH4OH jhq;fw; fiurYk;> rpwpjsT

fhl;bAk; NrHf;fg;gl;L tpisTf; fiury; 0.1moldm-3 nrwpTs;s EDTA

fiurYld; tYg;ghHf;fg;gl;lJ. fiury; nkd;rptg;gpy; ,Ue;J ePykhf khWk;

NghJ Njitg;gl;l EDTA ,d; fdtsT 22cm3 MFk;.

eilKiw II:- Nkw;gb td;ePH khjpupapd; gpwpnjhU 25cm3 khjpupahdJ rpyJsp nkjapy;

nrk;kQ;rs;fhl;b Kd;dpiyapy; Fwpj;j nrwpTila HCl ,dhy;

tYg;ghHf;fg;gl;lJ. fiury; nrk;kQ;rspy; ,Ue;J rptg;ghf khWk; NghJ

Njitg;gl;l HCl ,d; fdtsT 30cm3MFk;.

eilKiw III:- eilKiw II ,y; gad;gLj;jg;gl;l HCl fiurypd; 20cm3 ,Ds; kpifasT

KIO3, KI vd;gd NrHf;fg;gl;L ngwg;gl;l tpisTf;fiury; khg;nghUs; fhl;b

Kd;dpiyapy; 0.04moldm-3 Na2S2O3 ,dhy; tYg;ghHj;j NghJ mjd; 25cm3

Njitg;gl;lJ.

Nkw;gb td;ePH khjpupapd; epiyahd td;ikia [Permanent hardness] CaCO3 mgdm-3 rhu;ghff;

fhz;f? (Ca-40 , C- 12 , O-16 )

(2017/B/8/c)

(2016/B/8/c)

05) a. KMnO4 khjpup xd;W khrhf MnO2 I nfhz;Ls;sJ. ,k;khjpupapd; 3.32g jpzpTf;F rpwpJ

kpifahf KI ck; dil H2SO4 ck; ,lgg;ll;d. ntspgg; ll; I2 ,id Kww; hf epakpff; 2.0moldm-3

Na2S2O3 ,d; 45cm3 Njitg;gl;lJ

i. eilngWk; jhf;fq;fspd; <Lnra;j rkd;ghLfs; jUf.

ii. khjpupapy; KMnO4 ,d; J}a;ikapd; E}w;WtPjk; ahJ?

b) vitamin C vd;gJ Ascorbic acid C6H8O6 MFk;. ,J xU jho;j;Jq; fUtp. I2(aq) ,id gpd;tUkhW

jho;j;Jk;.

C6H8O6(aq) + I2(aq) → C6H6O6(aq) + 2HI(aq)

Njhlk;go kzKila nkd;ghdnkhd;wpidj; jahupg;gjw;F ,t; Ascorbic acid gad;gLfpwJ.

,g;ghdnkhd;wpd; 50.0cm3 MdJ 10.0cm3, 0.05moldm-3 KIO3 ePu;f;fiurYlDk; rpwpJ kpifahd KI

clDk; Nru;j;J ed;F FYf;fg;gl;lJ. jhf;fk; Kw;Wg; ngw;wgpd; tpisTf; fiurypy; vQ;rpAs;s

I2 ,id Kw;whf epakpg;gjw;F 0.030moldm-3, 30.0cm3, Na2SO3 fiury; Njitg;gl;lJ. vdpd;

nkd;ghdj;jpy; Ascorbic acid ,d; mikg;ig fhz;f.

(2015/B/8/c)

04)

tpilfs;

gy;Nju;T tpdhf;fs;

1) 4 2) 1 3) 5 4) 2 5) 3 6) 4 7) 2

fl;Liu tpdhf;fs;

01)

02)

03)

04) 04)

hgfkjgflkh