When 18.5 g of hgo(s) is decomposed to form hg(l) and o2(g), 7.75 kj of heat is absorbed at standard-state conditions. what is the standard enthalpy of formation (δh°f) of hgo(s)? –90.7 kj/mol

How many atoms of mg are present in 97.22 grams of mg? 6.022 × 1023 2.408 × 1024 4.818 × 1024 5.855 × 1025

What is the molar mass of ca(cio4)2

Before it was launched, a helium-filled balloon had a pressure of 201 kpa at a temperature of 27°c. at an altitude of 15,000 m, the pressure had decreased to 2.5 kpa and the temperature had dropped to -14 °c. the volume of the balloon increased to 59.3 m3. what is the original volume of the balloon? 13 m3 0.85 m3 0.077 m3 1.17 m3