General Chemistry Answers

30.0 g H2O at an unknown temperature is mixed with 27.0 g of water at 15.8oC in a coffee-cup calorimeter. If the final temperature of the mixture is 29.1oC, what is the initial temperature of the water?

An 88.5 –g piece of iron whose temperature is 78.8 ⁰ C is placed in a beaker containing 244 g of water at 18.8 ⁰ C.

      When thermal equilibrium is reached, what is the final temperature? (Assume no energy is lost to warm the         

       beaker and its surroundings). Cp of water is 4.184 J/g⁰C and the Cp of iron is 0.446 J/g ⁰C.

Write the equilibrium expression, K eq , for each of the following reactions:

1. 2 NO (g) + O 2(g) ⇌2 NO 2(g)

2. 4 HCl (g) + O 2(g) ⇌2 H 2 O (g) + 2 Cl 2(g)

3. NOCl (g) ⇌NO (g) + ½ Cl 2(g)

4. Fe 3+ (aq) + SCN - (aq) ⇌FeSCN 2+ (aq)

5. CaCl 2(s) ⇌Ca 2+ (aq) + 2Cl - (aq)

6. HC 2 H 3 O 2(aq) + H 2 O (l) ⇌ H 3 O + (aq) + C 2 H 3 O 2 - (aq)

7. MgO (s) + CO 2(g) ⇌ MgCO 3(s)

8. C (s) + CO 2(g) + 2Cl 2(g) ⇌ COCl 2(g)

9. Ca 3 (PO 4 ) 2(s) ⇌ 3 Ca 2+ (aq) + 2 PO 4 3- (aq)

10. ZnO (s) + CO (g) ⇌ Zn (s) +CO 2(g)

PLEASE ANSWER MY QUESTION QUICKLY !!

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

DEADLINE : 04/23/2022 11 : 00 PM

How to round off 0.01887006076 moles

Iron can be extracted from haematite, Fe2O3, using either C or CO2 as the reducing agent.

The reactions are shown below.

Fe2O3(s) + 3 C(s) → 2 Fe(s) + 3 CO(g) ΔH = +492.7 kJ /mol

Fe2O3(s) + 3 CO(g) → 2 Fe(s) + 3 CO2(g) ΔH = - 24.8 kJ/mol

Substance S° (J/ K·mol)

Fe2O3 (s) 87.4

Fe (s) 27.3

C (s) 5.7

CO (g) 197.6

CO2 (g) 213.6

Use available data given to:

1. Calculate the minimum temperature at which reduction with carbon is feasible

2. Prove by calculation that reduction with carbon monoxide is feasible at all temperatures

Determine the pH of a 0.20 M NH₃ solution.

1. Determine S for the reaction:

SO3(g) + H2O(l) —> H2SO4(l)

Given: S°(J/K·mol): 256.2 69.9 156.9

2. Calculate S for the reaction

SO2(s) + NO2(g) —> SO3(g) + NO(g)

Given: S°(J/K·mol): 248.5 240.5 256.2 210.6

3. Calculate S at 25C for the reduction of given these absolute entropies:

2PbO(s) + C(s) —> 2Pb(s) + CO2(g)

Given: S°(J/K·mol): 69.54 5.7 64.89 213.6

Predict whether the entropy change of the system in each of the following is positive or negative

1. O2(g) —> 2O(g)

2. N2 (g, 10 atm) —> N2 (g, 1atm).

3. 6CO2(g) + 6H2O(g) —> C6H12O6(g) + 6O2(g).

4. 2 H2 (g) + O2 (g) —> 2 H2O (l)

5. NH4Cl (s) —> NH3(g) + HCl (g)

A mixture of gases consists of N2, O2, H2 and F2. The total pressure of the mixture is 511.56 kPa. The pressure of the N2 is 584 mm Hg, the pressure of the O2 is 196 kPa and the pressure of the H2 is standard pressure. What is the pressure of the F2 (in mm Hg)?

Given the equation N2(g)+3H2(g)--->2NH3(g) if ∆H=-92.2kJ and ∆S=-0.1987kJ/K, what is ∆G for reaction at 475°C and at 5°C? Provide the answer in kJ. In each case, is the reaction spontaneous?