General Chemistry Answers

What is the heat required to melt 62.0 g of solid ammonia, NH₃, at its melting point? The ΔH° of fusion of ammonia is 5.97 kJ/mol. Use a molar mass with at least as many significant figures as the data given.

 Answer in kJ units

Given the reaction: 4 NH3(g) + 5 O2(g) —> 4NO (g) + 6H2O When 1.20 mole of ammonia reacts, how many moles of water are produced?

What is the heat required to melt 77.4 g of solid diethyl ether, (C₂H₅)₂O, at its melting point? The ΔH° of fusion of diethyl ether is 7.66 kJ/mol. Use a molar mass with at least as many significant figures as the data given.

 Answer in kJ Units

What is the heat required to vaporize 90.8 g of liquid ethanol, C₂H₅OH, at its boiling point? The ΔH° of vaporization of ethanol is 39.3 kJ/mol. Use a molar mass with at least as many significant figures as the data given.

Answer in kJ units

Calculate the amount of heat needed to melt 2.0 kg of iron at its melting point (1809 K) given that: ΔH_fus = 13.80 kJ/mol.

A. 27,600 kJ

B. 25,000kJ    

C. 494 kJ

D. 27.6 kJ

What is the heat required to vaporize 54.3 g of liquid ammonia, NH₃, at its boiling point? The ΔH° of vaporization of ammonia is 23.4 kJ/mol. Use a molar mass with at least as many significant figures as the data given.

 kJ units

75.0 moles of ethanol, C2H6O, in enough water to make 450 mL of solution.

The ksp of magnesium phosphate is 1 x 10 -24 at 25oC. If the magnesium phosphate is dissolved in 250. mL of water. How many grams of magnesium phosphate were dissolved (think about multiple units)

Chlorine trifluoride (ClF3) is used as a fluorinating agent. It may be used as an igniter and propellant in rockets and also used in nuclear fuel processing. Breathing Chlorine Trifluoride can irritate the lungs causing coughing and/or shortness of breath. Higher exposures can cause a build-up of fluid in the lungs (pulmonary edema), a medical emergency, with severe shortness of breath. Contact with the liquified gas can cause frostbite.

Using the given table below, formulate your own kind of problem; through providing hypothetical value for individual reactions, and also provide answer using the steps in getting the ΔH° of the reaction. ONLY condition is the reaction must be exothermic. 

ClF3(g) + O2 (g) → ½ Cl2O (g) + 3/2OF2 (g) ΔH° =

2ClF(g) + O2 (g) → Cl2O (g) + OF2 (g) ΔH° =

2OF2 (g) → O2 (g) + 2F2 (g) ΔH° = ClF (g) + F2 (g) → ClF3 (g) ΔH° = ?

Symbolic representation of decay type and product (iodine 123)