If 9.00  mol of hydrogen gas completely reacted with 3.000 mol of nitrogen gas at constant pressure, releasing 277 kJ of heat, which of the following thermochemical equations is correct?

A 30.0 L cylinder contains 122.0 g of oxygen gas at 25oC. What is the pressure of the gas in torr?

A 0.213 g sample of an organic compound with a molar mass of 386.0 g/mol was burned in the bomb calorimeter with a heat capacity of 2.54 kJ/K. The temperature in the calorimeter increased by 4.12 K. Calculate the energy of combustion of the compound in kJ/mol.

Which one of these compounds is an ionic compound?

What is the net ionic equation for the following molecular equation? BaCl2(aq) + K2SO4(aq) →   BaSO4(s)+ 2KCl(aq)

If the heat produced by the reaction of combustion of 1 mole of ethanol is 8 kJ/mol, (see the thermochemical equation below), how much heat in kJ is produced by the combustion of 155 g of ethanol at the same conditions (MMethanol= 46.07 g/mol)? C2H6O(g) + 3O2(g)  → 2CO2(g) + 3H2O(g);       ∆H°rxn=−1366.8 kJ/mol  

120.0g  of helium occupies a 15.25 L cylinder which is heated until the pressure is 150 atm. What is the temperature (in oC) of the gas?

Consider the following balanced reaction: Pb(s) + 2 Cl2(g)  → PbCl4(s) Starting with 30.0g of Cl2 (MMCl2= 70.90 g/mol) and excess Pb, determine the theoretical yield of PbCl4(MMPbCl4= 349.01 g/mol).

What is the percent by mass of oxygen in (NH4)2SO3?

Which is the correct coefficient for O2 in the following equation after balancing?       _C4H10  +  _O2  →  _CO2 + _H2O