How are dissolving water and ammonium nitrate an endothermic reaction

What is the ph of a 0.0010 m hno3? 1.0 3.0 4.0 5.0

In the space, show a correct numerical setup for calculating the number of moles of co2 present in 11 grams of co2

What is conserved in the reaction shown below? h2(g) + cl2 (g) --> 2hcl(g)a. mass onlyb. mass and moles onlyc. mass, moles, and molecules onlyd. mass, moles, molecules, and volume