Which of the following equations does not demonstrate the law of conservation of mass

Hey guys so i need to know what is _nh3+> nh4oh ~chemistry~

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

4. a 20-kg child is tossed up into the air by her parent. the child is 2 meters off the ground traveling 5 m/s. circle one: ke / gpe / both show your work for finding the values of each type of energy the object has: