Question

How much heat would it take to convert 60.0 g ice at 0.00˚C into liquid water at 20.0˚C?

The trend in polarizability from left to right across a period in the Periodic Table is due to …

	a.	decreasing electronegativity.
	b.	decreasing ionization energy.
	c.	increasing mass.
	d.	decreasing atomic size.

Answer 1

1.

Step 1

Heat required to melt ice

H1= Mass × Heat of fusion of ice

= 60.0 g × 334 J/g

= 20040 J.

Step 2

Heat required to increase the temperature of liquid water from 0⁰ c to 20⁰ c

H2 = Mass × specific heat × temperature

= 60 g × 4.184 J/g^oc × (20 - 0)^o c

= 5020.8 J.

Total heat needed

= H1 + H2

= (20040 + 5020.8 ) J

= 25060.8 J.

2.

Polarizability decreases from left to right across a period.

Larger atoms are more polarizable. Smaller atoms are less polarizable.

So , periodic trend in polarizability is due to decreasing atomic size.

Option d is correct.