9. In which case is more heat involved: mixing 100.0-g samples of 90 °C water and 80 °C water or mixing
100.0-g samples of 60 °C water and 10 °C water? As-
sume no heat is lost to the environment.
I know the answer is more heat in the second but why? how?

What is the mass of 8 moles of sodium atoms

The following reaction shows sodium carbonate reacting with calcium hydroxide. na2co3 + ca(oh)2 → naoh + caco3 how many grams of naoh are produced from 20.0 grams of na2co3? (molar mass of na = 22.989 g/mol, c = 12.01 g/mol, o = 15.999 g/mol, ca = 40.078 g/mol, h = 1.008 g/mol) 12.2 grams 15.1 grams 24.4 grams 30.2 grams

Select the most likely product for this reaction: koh(aq) + co2(g) – ? k2co3(aq) + h2o(1) k(s) + h2(g) + o2(g) k(s) + co3(9) +h2