Enthalpy, Energy, and Heat Quiz

Questions 1 - 3 refer to this diagram:

1

Which letter(s) represents the area where a liquid is heating up?

1

Which letter(s) represent the area where liquid and gas are in thermal equilibrium?

1

What is the melting point (the temperature) of this substance?

Questions 4 - 6 refer to this Pressure - Temperature Diagram

1

Which letter represents a substance in the solid phase?

2

What is the pressure and temperature where all three states of matter coexist?

1

What is the approximate temperature for the boiling point of this substance when the pressure is 30 atm?

2

a.  Using the specific heat table, which substance will take the most energy to change temperature?  _______ 

b.  Which substance will cool off the fastest? _______

2

If 200 grams of water is to be heated from 24.0°C to 100.0°C to make a cup of tea, how much heat (in kJ) must be added? The specific heat of water is 4.18 J/g∙C (formula q = m c (Tf - Ti))

1

How does heat flow?

1

In an exothermic reaction, heat energy is _______

1

Is this a Reaction pathway for an exothermic reaction or an endothermic reaction?

3

For the following thermochemical reactions indicate whether they are exothermic or endothermic

2 C2H6(g) + 7 O2(g) ---> 4 CO2(g) + 6 H2O(l) + 3120 kJ     _______ 

4 NO(g) + 6 H2O(l) + 1170 kJ  ---> 4 NH3(g) + 5 O2(g)    _______ 

N2(g) + 2 O2(g) + 67.6 kJ  ----> 2 NO2(g)      _______

1

Write this chemical equation as a thermochemical equation

2 C2H2 (g) + 5 O2 (g)  ---> 4 CO2 (g) + 2 H2O(l) ΔH = -2598.8 kJ

2

A 300 gram cube of lead is heated from 20 °C to 70 °C. How much energy was required to heat the lead? The specific heat of lead is 0.129 J/g°C.

2

How much heat is transferred when 147 g of NO2 reacts with excess H2O according to the following equation. (show your work, don't forget about signs indicating exothermic or endothermic reactions)

3 NO2(g) + H2O(l) ---> 2 HNO3(aq) + NO(g) + 138 kJ

Which letter(s) represents the area where a liquid is heating up?

Which letter(s) represent the area where liquid and gas are in thermal equilibrium?

What is the melting point (the temperature) of this substance?

Which letter represents a substance in the solid phase?

What is the pressure and temperature where all three states of matter coexist?

What is the approximate temperature for the boiling point of this substance when the pressure is 30 atm?

If 200 grams of water is to be heated from 24.0°C to 100.0°C to make a cup of tea, how much heat (in kJ) must be added? The specific heat of water is 4.18 J/g∙C (formula q = m c (Tf - Ti))

How does heat flow?

In an exothermic reaction, heat energy is _______

Is this a Reaction pathway for an exothermic reaction or an endothermic reaction?

Write this chemical equation as a thermochemical equation2 C2H2 (g) + 5 O2 (g) ---> 4 CO2 (g) + 2 H2O(l) ΔH = -2598.8 kJ

A 300 gram cube of lead is heated from 20 °C to 70 °C. How much energy was required to heat the lead? The specific heat of lead is 0.129 J/g°C.

How much heat is transferred when 147 g of NO2 reacts with excess H2O according to the following equation. (show your work, don't forget about signs indicating exothermic or endothermic reactions)3 NO2(g) + H2O(l) ---> 2 HNO3(aq) + NO(g) + 138 kJ

Write this chemical equation as a thermochemical equation

2 C2H2 (g) + 5 O2 (g)  ---> 4 CO2 (g) + 2 H2O(l) ΔH = -2598.8 kJ

How much heat is transferred when 147 g of NO2 reacts with excess H2O according to the following equation. (show your work, don't forget about signs indicating exothermic or endothermic reactions)

3 NO2(g) + H2O(l) ---> 2 HNO3(aq) + NO(g) + 138 kJ