This question is based in mole ratios. for every mole of cl2, 2 moles of NaCl will be produced. so half of the moles of NaCl gives the moles of Cl2 required. therefore divide 0.35 by 2
This can be done in the following way;
1 determining the heat required to convert 0° C ice to 0°C water
Heat of fusion of water = 334 J/g
Therefore; Heat = 50 g × 334 J/g = 16700 J
2. Determining the heat required to raise the temperature of water from 0° C to 100°C.
Specific heat of water is 4.18 J/g°C
Change in temperature is 100°C
Therefore; Heat = 50 g × 4.18 J/g°C × 100 = 20900 J
3. Determining the heat required to convert 100 ° C water to 100°C vapor
Heat of vaporization of water = 2257 J/g
Heat = Mass of water × heat of vaporization
Heat = 50 g × 2257 = 112850 J
4. Determining the heat required to go from 100° C to 120° vapor
specific heat of vapor = 2.09 J/g°C
Heat = mass × Specific heat of vapor × change in temperature
= 50 g × 2.09 ×(120-100) = 2090 J
Therefore the total heat required is
= 16700 J + 20900 J + 112850 J + 2090 J = 152540 J or 152.54 kJ
Gamma rays, because it is a decreasing wavelength