Millihemicontributors for burettes and pipettes

Table for millihemicontributors for burettes and pipettes

Test pipette into std. burette: std. burette into test burettes: 26 ml burette mark mode

Final Burette Reading (mL)	Volume (mL)	Burette/Pipette Factor	Millihemicontributor
1.5	24.5	1.020 & 0.980	520
1.4	24.6	1.016 & 0.984	516
1.3	24.7	1.012 & 0.988	512
1.2	24.8	1.008 & 0.992	508
1.1	24.9	1.004 & 0.996	504
1.0	25.0	1.000 & 1.000	500
0.9	25.1	0.996 & 1.004	496
0.8	25.2	0.992 & 1.008	492
0.7	25.3	0.988 & 1.012	488
0.6	25.4	0.984 & 1.016	484
0.5	25.5	0.980 & 1.020	480

For non-biased evaluation of students in an examination involving only a burette-pipette titration, the ratio of the burette factor and pipette factor for the examiner must be same as the ratio for each of the students. In other words, the sum of the millihemicontributors for the burette-pipette pair used must be same for the examiner and for each of the students. (A difference of 0.002 in this factor i.e., a difference of 2 in the sum of the millihemicontributors, introduces a relative error of magnitude 0.2% only.)

Table for millihemicontributors using a pseudo-standard burette of MHC (500 + x)* or a pseudo-standard pipette of MHC (500 – x)*

Test pipette into std. burette: std. burette into test burettes: 26 ml burette mark mode

Final Burette Reading (mL)	Volume (mL)	MHC for burette/pipette
1.5	24.5	520 + x, 520 – x
1.4	24.6	516 + x, 516 – x
1.3	24.7	512 + x, 512 – x
1.2	24.8	508 + x, 508 – x
1.1	24.9	504 + x, 504 – x
1.0	25.0	500 + x, 500 – x
0.9	25.1	496 + x, 496 – x
0.8	25.2	492 + x, 492 – x
0.7	25.3	488 + x, 488 – x
0.6	25.4	484 + x, 484 – x
0.5	25.5	480 + x, 480 – x

* Valid for small magnitude of x, i.e., for |x| < 5

101 102 103 104 105 106 107 108 109 110

111 112 113 114 115 116 117 118 119 120

121 122 123 124 125 126 127 128 129 130

131 132 133 134 135 136 137 138 139 140

141 142 143 144 145 146 147 148 149 150

151 152 153 154 155 156 157 158 159 160

161 162 163 164 165 166 167 168 169 170

171 172 173 174 175 176 177 178 179 180

181 182 183 184 185 186 187 188 189 190

191 192 193 194 195 196 197 198 199 200

201 202 203 204 205 206 207 208 209 210

211 212 213 214 215 216 217 218 219 220

221 222 223 224 225 226 227 228 229 230

231 232 233 234 235 236 237 238 239 240

241 242 243 244 245 246 247 248 249 250

251 252 253 254 255 256 257 258 259 260

261 262 263 264 265 266 267 268 269 270

271 272 273 274 275 276 277 278 279 280

281 282 283 284 285 286 287 288 289 290

291 292 293 294 295 296 297 298 299 300

301 302 303 304 305 306 307 308 309 310

311 312 313 314 315 316 317 318 319 320

321 322 323 324 325 326 327 328 329 330

331 332 333 334 335 336 337 338 339 340

341 342 343 344 345 346 347 348 349 350

351 352 353 354 355 356 357 358 359 360

361 362 363 364 365 366 367 368 369 370

371 372 373 374 375 376 377 378 379 380

381 382 383 384 385 386 387 388 389 390

391 392 393 394 395 396 397 398 399 400

401 402 403 404 405 406 407 408 409 410

411 412 413 414 415 416 417 418 419 420

421 422 423 424 425 426 427 428 429 430

431 432 433 434 435 436 437 438 439 440

441 442 443 444 445 446 447 448 449 450

451 452 453 454 455 456 457 458 459 460

461 462 463 464 465 466 467 468 469 470

471 472 473 474 475 476 477 478 479 480

481 482 483 484 485 486 487 488 489 490

491 492 493 494 495 496 497 498 499 500

501 502 503 504 505 506 507 508 509 510

511 512 513 514 515 516 517 518 519 520

521 522 523 524 525 526 527 528 529 530

531 532 533 534 535 536 537 538 539 540

541 542 543 544 545 546 547 548 549 550

551 552 553 554 555 556 557 558 559 560

561 562 563 564 565 566 567 568 569 570

571 572 573 574 575 576 577 578 579 580

581 582 583 584 585 586 587 588 589 590

591 592 593 594 595 596 597 598 599 600

601 602 603 604 605 606 607 608 609 610

611 612 613 614 615 616 617 618 619 620

621 622 623 624 625 626 627 628 629 630

631 632 633 634 635 636 637 638 639 640

641 642 643 644 645 646 647 648 649 650

651 652 653 654 655 656 657 658 659 660

661 662 663 664 665 666 667 668 669 670

671 672 673 674 675 676 677 678 679 680

681 682 683 684 685 686 687 688 689 690

691 692 693 694 695 696 697 698 699 700

701 702 703 704 705 706 707 708 709 710

Way of arranging physics, chemistry & biology half-day practical exam of 18 groups (A to R) in 9 days:

Day Bio Chy Phy Bio Chy Phy

Morning Session Afternoon Session

1 A B C D E F

2 G H I J K L

3 M N O P Q R

4 B C A E F D

5 H I G K L J

6 N O M Q R P

7 C A B F D E

8 I G H L J K

9 O M N R P Q

Ans. to Q. No. 4: Results of systematic qualitative analysis of organic compound:

Ans. to Q. No. : Results of systematic qualitative analysis of organic compound:

Experiment	Observation	Inference
(a) Test for unsaturation:
(b) Litmus test:
(c) NaHCO₃ test for –COOH:
(d) Neutral FeCl₃ test for phenol:
(e) Brady's test for carbonyl:
(f) Tests for –CHO: (i) (ii)
(g) Test for –NH₂ : (i) (ii)
(h) Muliken-Barker test for –NO₂:
(i) Test for alcoholic –OH:

Experiment	Observation	Inference
(a) Ignition test:
(b) Test for unsaturation:
(c) Litmus test:

Experiment	Observation	Inference
(a) Tests for halogens:
(b) Test for nitrogen:
(c) Test for sulphur:

Experiment	Observation	Inference
(a) NaHCO₃ test for —COOH
(b) Neutral FeCl₃ test for phenolic —OH
(c) Brady's test for C=O
(d) i) Fehling's test for —CHO
(d) ii) Schiff's test for —CHO
(e) Phenolic dye test for —NH₂
(f) Mulliken-Barker's test for —NO₂