A 3. 8 g sample was heated from 10. 5°C to 36. 5°C. It absorbed 44 A 3.8 g sample was heated from 10.5°C to 36.5°C. It absorbed 44.2 J of heat. What is the specific heat of this substance? 0.45 J/g °C

How are heat and temperature different? Heat is the total kinetic energy of particles in a sample. Temperature is the average kinetic energy of particles in a sample.

Which point represents liquid only? Which physical state has the lowest c? Which is greater: heat of fusion or vap.?

The increments on both scales are the same. It makes no difference whether T is expressed in °C or K. Why is this? The increments on both scales are the same.

How much heat is absorbed by 20 How much heat is absorbed by 20. g of gold when it is heated from 25°C to 35°C? 26J

On a cool morning (especially in the summer) fog develops over large bodies of water. Why? The water is warmer than the air (due to water’s high specific heat). Warm, evaporated water re-condenses as it hits the cool air, making fog.

What is “heat of formation” The amount of heat released as a compound forms.

Compounds whose heats of formation are highly negative do not exist are very unstable are somewhat stable are very stable

Calculate the change in enthalpy for: HCl + Ca(OH)2 --> H2O + CaCl2 H = -196.2 kJ

Calculate change in entropy for CH4 + H2O --> CO + 3H2 S = .215 kJ Determine if this reaction is spontaneous or non-spontaneous at 288.8K. Show your work. non-spontaneous G = 165.0 kJ (positive)

Name two things that could be done to speed the forward reaction for the following system: NH4Cl(s) + energy <--> NH3(g) + HCl(g) add heat add NH4Cl add NH3 remove HCl increase pressure

Compared to a single gas, a mixture of gases is more disordered less disordered equally disordered less favorable

Which statement is true of chemical equilibrium The reactants and products are present in equal concentrations The forward and reverse reactions are happening at the same rate. The reaction must contain gases. The reaction must be at room temperature. Both directions are at the same rate.