Answers Assignment 1 - Some Basic Concepts of Chemistry | Class 11th

Answers

Assignment - 1

Ans 1. (i) 4            (ii) 2

Ans 2.  0.86

Ans 3. 5960 kg m³

Ans 4.  We know  

⁰F = 9/5(⁰C) + 32

⁰F = 9/5(37) + 32

⁰F = 9 × 7.4 + 32 = 98.6 ⁰F

Ans 5. Let x be the common reading.

Then, C = F = x

We know the relation between ⁰C and ⁰F

⁰C=5/9 (⁰F-32), and substituting x for ⁰C and ⁰F, we get

x =5/9 (x-32)

x =5/9x - 5/9×32

x - 5/9x = 5×32/9

4/9x = - 5×32/9

x = - 5×32/4 = -40

So, -40 ⁰C = -40⁰F

Hence, at -40 degrees , the readings on the Celsius scale and the Fahrenheit scales are the same.

Ans 6. i). 4.8 × 10^-4                   ii) 2.34 × 10⁵

Ans 7. 3,3,3

Ans 8. (d) All of these

Ans 9. (b)  Calculate the average value of different titre values.

Then use the rule to determine the significant figures for mathematical calculation.  

                   Average value =  25.2  +  25.25  +  25.0  =   75.45

                                                                  3                            3                

= 25.15  = 25.2 mL  The number of significant figure is 3

Ans 10. (b)  The answer is to be reported up to same number of decimal places as that of the term with the least number of decimal places. This after rounding off 71.02 becomes 71.0.