To calculate the mass of unknown per kg water, we need to calculate the mass of the unknown substance in both trials and the mass of water in both trials. This will allow us to find the ratio of the mass of the unknown substance to the mass of water.
First, let's calculate the mass of the unknown substance in Trial 1:
Mass of unknown substance = Mass of full beaker - Mass of empty beaker
= 207.245g - 163.20g
= 44.045g
Now, let's calculate the mass of water in Trial 1:
Mass of water = Mass of full beaker - Mass of solid unknown
= 207.245g - 5.034g
= 202.211g
Next, let's calculate the mass of the unknown substance in Trial 2:
Mass of unknown substance = Mass of full beaker - Mass of empty beaker
= 204.97g - 163.25g
= 41.72g
Now, let's calculate the mass of water in Trial 2:
Mass of water = Mass of full beaker - Mass of solid unknown
= 204.97g - 5.034g
= 199.936g
Finally, let's calculate the mass of unknown per kg water for both trials:
Mass of unknown per kg water in Trial 1 = (Mass of unknown substance / Mass of water) * 1000
= (44.045g / 202.211g) * 1000
= 217.83 g/kg
Mass of unknown per kg water in Trial 2 = (Mass of unknown substance / Mass of water) * 1000
= (41.72g /199.936g) * 1000
= 208.65 g/kg
So, the mass of unknown per kg water is 217.83 g/kg for Trial 1 and 208.65 g/kg for Trial 2.