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Use the following enthalpies of formations (∆Hof): C2H5OH(l) H2O(l) CO2(g) ∆Hof -278 kJ/mol -286 kJ/mol -394 kJ/mol to calculate the standard enthalpy of reaction (∆Horxn) for the following reaction: C2H5OH(l) + 3O2(g) → 2CO2(g) + 3H2O(l) ∆Horxn = ?

What is  the final pressure of a gas that is expanded from 0.755 L at 24.0oC and 1.25 atm to 2.00 L at 33.0oC?

A sample of 0.725 mol of SO2 occupies a volume of 1.50 L. What will the volume be if the number of moles of SO2 is increased to 0.975 mol, with no change in temperature or pressure ?

An oxygen sample of 1.62 L is at 0.911 atm and 30.0°C.How many moles of oxygen are in the sample?

If 12.6 g of CuSO4 (molar mass 159.61 g/mol) is dissolved in water to make a 0.350 M solution of CuSO4, what is the volume of the solution in milliliters? Show all your work for full credit. Use the correct number of significant figures.

Perform the following conversions between energy units. a) 721 kJ  =  [i_1] ×10[i_2] J b) 3255 kcal  =  [ii_1] × 10[ii_2] kJ c) 5.50 ×106 J  =  [iii_1] × 10[iii_2] kcal

How many double bonds are present in the Lewis structure of NO2- in which the formal charge of N is zero?

Calculate the enthalpy change for the following reaction: 2CO(g) + 4H2O(l) → 2CH4(g) + 3O2(g) ∆H = ? Given the following reactions and their ∆H values: CH4(g) + 2O2(g) → CO2(g) + 2H2O(l) ∆H = -890.0 kJ 2CO(g) + O2(g) → 2CO2(g) ∆H = -566.0 kJ

Calculate the pressure of 2520 moles of hydrogen gas stored at 27.0oC in the 180. L storage tank of modern hydrogen-powered car.

What are the bond angles around a central atom with sp hybridized orbitals?