The heat cause 300g water temperature increase from 20 to 26 celcius. The heat transferred would be: 300g * (26 °C -20 °C) *4.2 joule/gram °C= 7560J
The unknown substance is added to the water, so its final temperature should be the same as the water. The calculation would be:
7560J= 124g * (100-26)* specific heat
specific heat= 7560J / 124g / 74 °C= 0.8238 J/gram °C
Are you sure it isn’t SO3+H2O = H2SO4 because that would be combination (synthesis) A+ B=AB
Or SO3 + H2SO4 = H2S2O7
Because that would also be synthesis
