A50 cm^3 block of iron is removed from an 800 degrees celsius furnance and immediately dropped into 200 ml of 20 degrees celsius water. what percentage of the water boils away?

 % of water boils away= 12.64 %

Explanation:

given,

volume of block  = 50 cm³ removed from temperature of furnace = 800°C

mass of water = 200 mL = 200 g

temperature of water  = 20° C

the density of iron = 7.874 g/cm³ ,

so the mass of iron(m₁)  = density × volume = 7.874 × 50 g = 393.7 g

the specific heat of iron C₁ = 0.450 J/g⁰C

the specific heat of water Cw= 4.18 J/g⁰C

latent heat of vaporization of water is L_v = 2260 k J/kg = 2260 J/g

loss of heat from iron is equal to the gain of heat for the water

m₂ = 25.28 g

25.28 water will be vaporized

% of water boils away =

 % of water boils away= 12.64 %

frequency or wavelenth of em radiation in a vacuum