Chemistry Answers

What is an ordinate bond? How different is it from coordinate bonds?

36.42ml to nl

During this time of pandemic, most of the blood banks run out of blood. Have

experience to get a pack of blood in a blood bank. Why is it necessary to bring with

you a storage box with ice on it?(Relation to Gibb's Free Energy- Spontaneous Process)

Topic: Enthalpy and Hess Law

1. Calculate the heat of hydrogenation of ethane, C2H4 given the following thermochemical equations:

2 C (graphite) + 3 H2 (g) ---> C2H6 (g). ∆Hf= -84.5 kJ/mol

2 C (graphite) + 2 H2 (g) ---> C2H4 (g). ∆Hf= 52.3 kJ/mol

2. Calculate the ∆H for the reaction:

CS2 (I) + 2 O2 (g) CO2 (g) + 2 SO2 (g)

Given:

∆Hf CO2 (g) = - 393.5 kJ/mol

∆Hf SO2 = - 296.8 kJ/mol

∆Hf CS2 (I) = 87.9 kJ/mol

Give the essential condition for the reaction between chlorine and butane?What type of reaction is this?

How many grams of potassium chloride are produced if 15 grams of potassium chlorate decomposes?"

For the following reaction, 148 grams of calcium hydroxide are allowed to react with 73.0 grams of hydrochloric acid .

• Ca(OH)₂ (aq) + 2 HCl (aq)  CaCl₂ (aq) + 2 H₂O (l)

What is the FORMULA for the limiting reagent?

What is the maximum amount of calcium chloride that can be formed?  

What amount of the excess reagent remains after the reaction is complete?  

Which of these changes are endothermic? Which are exothermic? (You must know the names for each of the phase changes.) please explain

a) Melting of ice

b) CH4 (g) + 2 O2 (g) --> CO2 (g) + 2 H2O (g) + 882 kJ

c) Deposition of iodine

d) NH4Cl (s) --> NH4Cl (aq) ΔH° = + 14.7 kJ/mol

e) Calcium oxide solid dissolving in water causes a temperature increase

Which of these changes are endothermic? Which are exothermic? (You must know the names for each of the phase changes.)

a) Water accumulating on grass early in the morning

b) Solidification of liquid magma

c) 3NO2 + H2O --> 2HNO3 + NO ∆H = - 138 kJ

d) 6CO2 + 6H2O + 2803 kJ --> C6H12O6 + 6O2

e) Sugar crystalizing in a saturated solution.

1. What is the sign and magnitude of the heat associated with a process with 342 J of work is done and there is an increase in the internal energy of 5.43 kJ?
2. What is the sign and magnitude of the work associated with a process where the system lost 1.23 kJ of heat and the internal energy was reduced by 921 J?
3. The volume of a balloon expands by 230 mL against an atmospheric pressure of 745 mm Hg. Assuming the resistance of the latex to be negligible, how much work is associated with the process?

1. How much heat is released when 9.22 grams of glucose C6H12O6 reacts according to the following equation?

C6H12O6 + 6O2 --> 6CO2 + 6H2O ∆H = -2803 kJ

2. How much heat is absorbed during photosynthesis when 9.22 grams of glucose C6H12O6 is produced?

6CO2 + 6H2O --> C6H12O6 + 6O2 ∆H = +2803 kJ

3. How much heat is released when 147 grams of NO2(g) is dissolved in excess water?

3NO2 + H2O --> 2HNO3 + NO ∆H = - 138 kJ

4. Calculate the heat released when 74.6 grams of SO2 reacts according to the following equation.

2SO2 + O2 --> 2SO3 ∆H = -99.1 k