Here, Z is:

1.  SO₃

2.  Colloidal sulphur

3.  Gaseous sulphur

4.  Solid Sulphur

Which of the following soap/detergent is least, reduce space biodegradable?

1.  ${\mathrm{CH}}_3-{\left({\mathrm{CH}}_2\right)}_{11}-{\mathrm{OSO}}_2\mathrm{Na}$

2.  ${\mathrm{C}}_{17}{\mathrm{H}}_{35}-\mathrm{COONa}$

3.  

4.  

Buna-N, a synthetic rubber is copolymer of:

1.  ${\mathrm{H}}_2\mathrm{C}=\mathrm{CH}-\mathrm{CH}={\mathrm{CH}}_2 \mathrm{and} {\mathrm{H}}_5{\mathrm{C}}_6-\mathrm{CH}={\mathrm{CH}}_2$

2.  ${\mathrm{H}}_2\mathrm{C}=\mathrm{CH}-\mathrm{CN} \mathrm{and} {\mathrm{H}}_2\mathrm{C}=\mathrm{CH}-\mathrm{CH}={\mathrm{CH}}_2$

3.  

4. 

1.  28.5 kJ

2.  17.1 kJ

3.  45.7 kJ

4.  1 .7 kJ

1.  K⁺ < Ca2⁺ < Mg2⁺ < Be2⁺

2.  Be2⁺ < K2⁺ < Ca2⁺ < Mg2⁺

3.  Mg2⁺ < Be2⁺ < K⁺ < Ca2⁺

4.  Ca2⁺ < Mg2⁺ <Be⁺ < K⁺