A student calculated the number of moles of carbon dioxide to be 0.30 moles in a 200.0 g sample of a gaseous mixture. What is the percent composition of carbon dioxide? (molar mass = 44.01 g/mol) A. 0.066%
B. 13%
C. 30%
D. 6.6%

When 13.3 g koh is dissolved in 102.7 g of water in a coffee-cup calorimeter, the temperature rises from 21.4 °c to 31.53 °c. what is the enthalpy change per gram of koh (j/g) dissolved in the water? * take the density of water as 1.00 g/ml. * assume that the solution has a specific heat capacity of 4.18 j/g*k. enter to 1 decimal place. do not forget the appropriate sign /(+). canvas may auto-delete the (+) sign