General Chemistry Answers

Heterogeneous reactions are reactions that occur between reactants that are of different states of matter. For example, UF5 solid reacts with hydrogen gas as shown below.UF5(s) + H2(g) ⇄ UF3(g) + 2HF(g)

A sample of solid UF5 is placed in a rigid 1 L container. H2 gas is added and the

container is heated to 1000C & the reaction above takes place.

When the system is at equilibrium, the partial pressure of H2(g) is 0.800 atm and the partial pressure of UF3(g) is 4.0510-4 atm.

a. Write the equilibrium constant expression for the reaction.

b. Calculate the partial pressure of HF(g) at equilibrium at 1000C.

c. Calculate the value of the equilibrium constant for the reaction at 1000C.

d. Calculate the Gibbs free-energy change, deltaG0, for the reaction at 1000C.

Using the standard reduction potentials, determine whether the following reactions are spontaneous under standard conditions:

A. Magnesium reducing chlorine to chloride ions

B. Silver reducing hydrogen ions to hydrogen

C. Cl₂ (g) + 2 i^-1 (aq) = 2Cl^-1 (aq) + i² (s)

How many grams of H2O will be formed when 32.0 g H2 is allowed to react with 16.0 g O2 according to 2 H2 + O2 → 2 H2O

"Standard Redox Reactions"

Using the standard reduction potentials, determine whether the following reactions are spontaneous under standard conditions:

A. Magnesium reducing chlorine to chloride ions

B. Silver reducing hydrogen ions to hydrogen

C. Cl₂ (g) + 2 i^-1(aq) = 2Cl^-1 (aq) + i₂ (s)

A cell using Zn/Zn+2 (aq, 1M) and H₂ / H⁺¹ (aq, 1M) generates a cell potential of + 0.67 V under standard conditions.

A. Write the half-cell reaction at the anode.

B. Write the half-cell reaction at the cathode.

C. Write the electrochemical cell notation.

D. Calculate the standard reduction potential at the anode.

1. The phase diagram for a pure substance is given below. The solid sublimes
   
2.   
3. at 400 K and 200 atm.
4. at 200 K and 100 atm.
5. at 300 K and 100 atm.
6. at 300 K and 75 atm.
7. if warmed at any pressure below 50 atm.

How much energy is required to convert 12.00 g of ice at -5.00 °C to liquid water at 2.50 °C?

What volume of distilled water is needed to make an 3 M solution of HCl acid using 5 moles of HCl?

dissociation equation of O₂

Liquid bromine and gaseous fluorine can undergo a synthesis reaction in the presence of heat

to produce bromine pentafluoride, a covalent compound. How many molecules of bromine react

with 1.11 X 1020 molecules of fluorine?