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please help in my doubt

please help in my doubt

by 123iitjee.com Support -
Number of replies: 1

This post is made by DIBYADARSHI MISHRA .

1.WHICH OF THE FOLLOWING IS THE STRONGEST BASE?

A)HC(TRIPLE BOND)C- B)CH2(DOUBLE BOND)CH- C)CH3CH2-

D)NH2-

ANS-C

2.THE AGE OF A WOODEN ARTIFACT WAS DETERMINED BY CARBON-14 DATING.THREE DIFFERENT MEASUREMENTS GAVE VALUES OF 6925,4815 AND 5485 YEARS.WHICH IS THE BEST VALUE TO REPORT FOR THE AGE OF THIS ARTIFACT?

A)5700 YEARS B)5740 YEARS C)5741 YEARS D)6000 YEARS

ANS-D

3.HOW MANY UNIT CELLS ARE PRESENT IN A CUBE-SHAPED IDEAL CRYSTAL OF NaCl OF MASS 1g.

ANS-2.57*1021

In reply to 123iitjee.com Support

Re: please help in my doubt

by aditya gopi -
answer 1>

first take the conjugate acids.

you would find ethane CH3-CH3 is least acidic.

thus (c) must be the answer.


answer 2>

looking at the options i would have told (c)
since it is the average.

answer 3>

1g of NaCl has (6.023 * 10^23)/58.5 particles
each unit cell has 4.

thus Undetermined error: @@(6.023*10^23)/(58.5 * 4) = 2.57 * 10^21@@