Two basic properties of the gas phase are A.) a definite shape and a definite volume

SOLID

B.) a definite shape but no definite volume C.) no definite shape but a definite volume

LIQUID

D.) no definite shape and no definite volume

Which substance has vibrating particles in regular, fixed positions?

A.) Ca(s) B.) Hg(l) C.) Cl 2 (g) D.) CaCl 2 (aq)

The circle on the left shows a magnified view of a very small portion of liquid water in a closed container. What would the magnified view show after the water evaporates?

Boiling water is a physical change A,B, and D - Water molecules are not decomposed into hydrogen and oxygen gas (hydrogen is flammable and oxygen supports combustion, if these gases were created there would be explosions every time you boiled water) C – the particles do not vanish (Law of Conservation of Matter)

E – when water molecules boil, they remain water, the particle simply move farther away from one another

Which grouping of the three phases of bromine is listed in order from left to right for increasing distance between bromine molecules?

A.) gas, liquid, solid B.) liquid, solid, gas C.) solid, gas, liquid D.) solid, liquid, gas

Which phase change is an exothermic process?

A.) CO 2 (s)  CO 2 (g) B.) NH 3 (g)  NH 3 (l) C.) Cu(s)  Cu(l) D.) Hg(l)  Hg(g)

Which change is exothermic?

A.) freezing of water B.) melting of iron C.) vaporization of ethanol D.) sublimation of iodine

A 1.0-gram sample of solid iodine is placed in a tube and the tube is sealed after all of the air is removed. The tube and the solid iodine together weigh 27.0 grams. The tube is then heated until all of the iodine sublimes and the tube is filled with iodine gas. Will the weight after heating be: A.) less than 26.0 grams. B.) 26.0 grams. C.) 27.0 grams. Particle mass does not depend on phase D.) 28.0 grams. E.) more than 28.0 grams.

Assume a beaker of pure water has been boiling for 30 minutes. What is in the bubbles in the boiling water? A.) Air B.) Oxygen gas and hydrogen gas C.) Oxygen D.) Water vapor E.) Heat

A glass of cold milk sometimes forms a coat of water on the outside of the glass (Often referred to as 'sweat'). How does most of the water get there?

A.) Water evaporates from the milk and condenses on the outside of the glass.

B.) The glass acts like a semi-permeable membrane and allows the water to pass, but not the milk.

C.) Water vapor condenses from the air.

D.) The coldness causes oxygen and hydrogen from the air combine on the glass forming water.

You take a swim in the swimming pool. Although it is a hot day when you come out, you feel cold. Which of the following statements is TRUE?

A.) The water in the pool is warmer than the air B.) The water in the pool is colder than the air C.) The water on your skin gets cold when you step out of the pool D.) The water on your skin evaporates

L



G is endothermic, absorbing heat energy from your body

At which temperature will equilibrium exist for the system below?

H 2 O(s) ↔ H 2 O(l) A.) 0 K B.) 100 K C.) 273 K D.) 373 K

A pot of water is brought to a boil. The temperature of the water when it started to boil was 100.0ºC. What do you expect the thermometer to read after boiling for 15 minutes?

A.) Below 100.0ºC B.) 100.0ºC C.) 105.0ºC D.) 115.0ºC E.) Above 115.0ºC

As a solid substance absorbs heat at its melting point, the melting point will A.) decrease B.) increase C.) remain the same

The graph represents the uniform heating of a solid, starting below its melting point. Which portion of the graph shows the solid and liquid phases of the substance existing in equilibrium?

A.) AB B.) BC

S S,L

C.) CD

L

D.) DE

L,G

E.) EF

G

The graph shown represents the relationship between temperature and time as heat is added uniformly to a substance, starting when the substance is a solid below its melting point. Which portions of the graph represent times when heat is absorbed and potential energy increases while kinetic energy remains constant?

A.) A and B B.) B and D C.) A and C D.) C and D Potential energy changes when temperature (KE) does not

The graph represents the uniform cooling of a substance, starting with the substance as a gas above its boiling point. During which interval is the substance completely in the liquid phase?

A.) AB

G

B.) BC

G,L

C.) CD

L

D.) DE

L,S

The graph (see image) represents the uniform heating of a substance, starting with the substance as a solid below its melting point.

Which line segment represents an increase in potential energy and no change in average kinetic energy?

Temperature (KE) changes on the slants, Potential Energy on the Plateus

As ice melts at standard pressure, its temperature remains at 0ºC until it has completely melted. Its potential energy A.) decreases B.) increases C.) remains the same The particles move further apart, but the kinetic energy remains the same

The heat of fusion is defined as the energy required at constant temperature to change 1 unit mass of a A.) gas to a liquid B.) gas to a solid C.) solid to a gas D.) solid to a liquid Melting/Fusion

In which equation does the term "heat" represent heat of fusion?

Heat of Vaporization

What amount of heat is required to completely melt a 29.95 gram sample of H 2 O(s) at 0ºC?

A.) 334 J B.) 2260 J C.) 1.00 × 10 3 J D.) 1.00 × 10 4 J Q = mH fus = (29.95g)(334J/g)

How much energy is released when 36.0 grams of steam condenses into liquid water?

A.) 12.0 kJ B.) 81.4 kJ C.) 195 kJ D.) 1580 kJ Q = mHvap = (36.0g)(2260J/g)

How many joules are needed to vaporize 2.00 g of liquid ethanol at its boiling point, 78.0ºC? (The heat of vaporization for ethanol is 854 J/g) A.) 156 B.) 540 C.) 854 D.) 1710 Q = mH vap = (2.00g)(854J/g) Temperature is not included as this is a phase change (it will remain at 78)

As the temperature of a liquid increases, its vapor pressure A.) decreases B.) increases C.) remains the same

As the pressure on the surface of a liquid decreases (atmospheric pressure), the temperature at which the liquid will boil A.) decreases B.) increases C.) remains the same The atmospheric pressure is lower, meaning that the vapor pressure will be lower, and will cause boiling to occur at a lower temperature