7. How much energy in KJ is released when 15.0 g of steam at 100.0 degrees Celsius is condensed and then frozen to ice at 0.0 degrees Celsius?

-6.27 kj

Explanation:

Given data:

Energy released = ?

Mass of steam = 15 g

Initial temperature = 100°C

Final temperature = 0°C

Solution:

Specific heat capacity:

It is the amount of heat required to raise the temperature of one gram of substance by one degree.

Specific heat capacity of water is 4.18 j/g.°C

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

ΔT =  0°C - 100°C = -100°C

Q = 15g × 4.18 j/g.°C  × -100°C

Q = -6270 j

J to KJ:

-6270 j/1000 = -6.27 kj

your parents i think this could be it

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.