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Mole, Mass, Enthalpy, and Energy Change Problems

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1. Which is not a solution? brass, fog, hydrochloric acid, or wine

2. How Many Moles of CuO can be produced from 0.0450 mol if Cu2O in the following reaction? 2 Cu2O(s) + O2(g) -> 4 CuO(s).

3. Methane and Oxygen react to form carbon dioxide and water. What mass of water is formed if 3.2g of Methane reacts with 12.8g of oxygen to produce 8.8g of carbon dioxide? 7.2 g, 8.8g, 14.8g, or 16.0g

4. For the reaction I2(g) ->I2(s), Delta H deg = -62.4 KJ at 25 deg C.
Based on the data, at 25 deg C
a. delta H deg vap = -62.4 kJ / mol
b. delta H deg vap = 62.4 kJ / mol
c. delta H deg sub = -62.4 kJ / mol
d. delta H deg sub = -62.4 kJ / mol

5. When 200 mL of 0.150 M of hydrochloric acid is added to 125 mL of 0.175 M Mg(OH)2 the resulting solution will be? acidic, basic , or neutral

6. Calculate the energy change in kJ / mol for the reaction
Li+(g) + F- (g) ->; Li(g) + F(g) using the following information:

Li(g) -> Li+ (g) + e- +520 kJ / mol
F(g) + e- ->; F-(g) -328 kJ / mol

a. -848 kJ / mol
b. -192 kJ / mol
c. + 192 kJ / mol
d. + 848 kJ / mol

7.Which statement about elemental analysis by combustion is not correct?

a, Carbon is determined from the amount of CO2 formed
b. Hydrogen is determined from the amount H2O formed
c. Oxygen is determined from the amount of H2O formed
d. Only carbon and hydrogen can be determined directly fromCO2 and H2O

8. When K2SO4(aq) and Pb(NO3)2(aq) are mixed a white colored precipitate forms, which is ? KNO3, K2SO3, Pb, or PbSO4

9. What is the Celsius temperature of 100.0g of chlorine gas in a 40.0 L container at 800mm Hg? -91 deg C, 91 deg C, 182 deg C, 364 deg C

10.Two aqueous solutions A and B, are separated by a semi permeable membrane. The pressure of solution A immediately begins to decrease. Which of the following is true?

a. Solvent molecules a re moving from solution B into solution A
b. The initial osmotic pressure of solution B is greater than that of solution A
c. The solvent molecules are moving from the solution of higher osmotic pressure to that of lower osmotic pressure.
d. Both B and C are true statements.

11. For the reaction 2CH4 (g) + 3 Cl2(g) + 3 Cl2 -> 2CHCl3 (l) + 3H2 (g).
Find delta H deg f for CH4 (g).
delta H deg = -118.6 kJ.
delta H deg f = -134.1 kJ / mol for CHCl3 (l) .

a. -193.4 kJ / mol
b. -74.8 kJ / mol
c. 74.8 kJ / mol
d. 193.4 kJ /mol

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Solution Summary

This solution contains step-by-step calculations and explanations to address the general chemistry concepts of mole, mass, enthalpy, and energy change problems.

See Also This Related BrainMass Solution

Energy, q, w, Enthalpy, and Stoichiometry II and Specific Heat

Problem 1 - Energy, q, w, Enthalpy, and Stoichiometry
Consider the following reaction:

2Mg(s)+O2(g)>>2MgO(s)ΔH = -1204kJ

1) Is this reaction exothermic or endothermic?

2) Calculate the amount of heat transferred when 2.1 g of Mg(s) reacts at constant pressure.
Express your answer using two significant figures.

3)How many grams of MgO are produced during an enthalpy change of -94.0 kJ ?

4)How many kilojoules of heat are absorbed when 7.80 g of MgO(s) is decomposed into Mg(s) and O2(g) at constant pressure?

Problem 2 - Specific Heat

The specific heat of iron metal is 0.450 J/g*K
How many J of heat are necessary to raise the temperature of a 1.10 - Kg block of iron from 26.0 Celsius degrees to 88.0 Celsius degrees?

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