Chemistry Chapter 11 Quiz

Nelson Chemistry Chapter 11 Quiz Click on the correct answer

1 The standard heat of formation for one mole of liquid water is +4.19 J/goC +6.03 kJ/mol +40.8 kJ/mol -285.8 kJ/mol 2

Use the following information to answer this question.

Q2(g) ------> Q(g) + Q(g) delta H = +100 Kj/mol X2(g) ------> X(g) + X(g) delta H = + 50 kJ/mol Q(g) + X(g) -----> QX(g) delta H = -200 kJ/mol If Q2(g) reacted with X2(g) to form QX(g), the statement that would best describe this reaction is that: intramolecular bonding in sample X2(g) is stronger than in Q2(g) intermolecular bonding in sample X2(g) is weaker than in Q2(g) the reaction is endothermic the reaction is exothermic 3

Use the following information to answer this question.

The molar heat of combustion for ethylene glycol, C2H4(OH)2(l), is -1181.2 kJ/mol when the products of combustion are gases. The heat of formation of ethylene glycol is: +590.6 kJ/mol -331.2 kJ/mol -500.7 kJ/mol -1181.2 kJ/mol 4 The heat of formation of sodium chlorate [NaClO3(s)] is -53 kJ/mol. The balanced equation which expresses this information is Na(s) + Cl2(g) + O2(g) -------> NaClO2(g) + 53 kJ Na(s) + 1/2Cl2(g) + 3/2O2(g) -----> NaClO3(s) + 53 kJ Na(s) + 1/2Cl2(g) + 3/2O2(g) + 53 kJ -------> NaClO3(s)

Na(s) + Cl2(g) + 3O2(g) ------> NaClO3(g) + 53 kJ 5

Use the following information to answer this question.

C(s) + 2H2(g) -----> CH4(g) delta H = -74.8 kJ C(s) + 2Cl2(g) ------> CCl4(l) delta H = -106.4 kJ 1

/2H2(g) + 1/2Cl2(g) -----> HCl(g) delta H = - 92.3 kJ

The heat of reaction for CH4(g) + 4Cl2(g) -----> CCl4(l) + 4HCl(g) is -123.9 kJ -216.2 kJ -273.5 kJ -400.8 kJ 6

Use the following information to answer this question.

6CO2(g) + 6H2O(l) + 2802.7 kJ ------> C6H12O6(s) + 6O2(g) The amount of CO2(g) required to react so that 2.2 x 103 kJ are absorbed is: 7.6 mol 6.0 mol 4.7 mol 1.3 mol 7 A reaction has a positive delta H value. This means that the reaction is exothermic the reaction releases energy during the reaction, the surroundings get colder the heat content of the products is less than that of the reactants. 8 Which statement is correct? Hf(products) = Hf(reactants) delta H = nHf(products) - nHf(reactants) delta H = nHf(reactants) - nHf(products) nHf(products) = delta H - nHf(reactants) 9

Given the following thermochemical data:

1) C2H2(g) + 5/2O2(g) -----> 2CO2(g) + H2O(l) delta-H = -1.30 x 103 kJ 2) C2H6(g) + 7/2O2(g) -----> 2CO2(g) + 3H2O(l) delta-H = -1.56 x 103 kJ

3) H2(g) + 1/2O2(g) -----> H2O(l) delta-H = -2.86 x 102 kJ What is the delta-H for the reaction: C2H2(g) + 2H2(g) -----> C2H6(g) delta-H = ? -2.60 x 101 kJ -3.12 x 102 kJ -5.72 x 102 kJ -5.46 x 103 kJ 10 The change that is predicted to release the largest quantity of energy is C(s) + O2(g) -----> CO2(g) 2NO2(g) -----> N2O4(g) 14 0 14 6C -----> -1e + 7N CO2(s) -----> CO2(g)

Science Quiz: Chemistry 1) How many moles of sugar are required to make 4 L of a saturated solution of sugar having a concentration of 0.6 mole per liter? a) 2.4 moles

b) 1.2 moles c) 1.8 moles d) 0.6 moles 2) Sugar is not infinitely soluble in water because: a) when you mix enough sugar into water the solution eventually solidifies. b) of the strong c) of the strong d) there is only molecules to

attractions that occur between sugar molecules attractions that occur between water molecules so much space between water molecules for sugar fit

3) Covalent and ionic bonds differ in that: a) ionic bonds don't involve the sharing of electrons b) covalent bonds are more permanent c) covalent bonds are much less common d) ionic bonds are electrical by nature

4) The outer shells of two atoms that are covalently bonded: a) cancel each other

b) have increasing capacities for electrons c) overlap d) repel 5) The boiling temperature of water is much higher than methane because water molecules are:

a) composed of fewer atoms b) more massive c) smaller d) polar 6) Are there hydrogen bonds between water molecules in the liquid phase? a) No, and if there were, the water would just be ice (a solid) b) Yes, and they are continually breaking and reforming c) Yes, but they rarely occur d) No, otherwise the water molecules would not be able to tumble over one another

7) Detergents differ from soaps in that: a) their ionically charged heads are derivatives of sulfur b) they can be broken down by microorganisms c) detergents are human-made while soaps are produced naturally d) detergents are less able to penetrate grease than soaps

8) A pH of 7 signifies a solution which is: a) basic b) salt c) acidic d) neutral 9) How many different isomers are possible for a hydrocarbon with the molecular formula C4H10? a)1 b) 2 c) 3 d) 5 10) Which of these contains the carbonyl group? a) Ketones b) Aldehydes c) Esters d) All of these bccabbdbdc

Temperature The hotter something is the faster the atoms are jiggling around. Let's say we have two objects, one hot, the other cold, and we bring them together. There's more jiggling around going on in the hot object.

There is an exchange of kinetic energy between the two objects.

Given enough time this energy will become evenly distributed between the two objects. The atoms in the hotter object will have slowed down while the atoms in the colder object will have speeded up. Thus we see that heat is always passed from the hotter to the colder object.

One of the earliest ways of measuring temperature was the thermometer that is based on the expansion in the volume of certain liquids with an increase in temperature. Gabriel Daniel Fahrenheit invented the mercury thermometer in 1714. Before that alcohol was used. Standardizing of a temperature scale and

calibrating thermometers allows one to compare the temperatures of systems that exist at different times and places.

Temperature scales The Fahrenheit scale is in general usage in English-speaking countries. Chemists usually use the Celcius scale, established by Anders Celcius (1701-1744), which assigns zero degrees to the freezing point of airsaturated water and 100 degrees to boiling water at one atmosphere. In the Fahrenheit scale water freezes at 32 degrees and boils at 212 degrees.

So a temperature difference of 100° C is 180° F. The ratio 100/180 can be reduced to 5/9. To convert from degrees F to degrees C we have to subtract 32 and multiply by 5/9. To convert from degrees C to degrees F we have to multiply by 9/5 (which gives you Fahrenheit sized degrees) and then add 32 (which adjusts for the offset). Let's convert the boiling temperature of water as 212° F to Celcius. 212 - 32 = 180. 180 x 5/9 = 100. A comfortable room temperature is 72° F. Let's convert that to Celcius. 72 - 32 = 40. 40 x 5/9 = 22.2. 25° C is used as a "standard" temperature. Let's convert that to Fahrenheit. 25 x 9/5 = 45. 45 + 32 = 77.

The 32 that we add or subtract is in degrees Fahrenheit, so we always add or subtract to the temperature in Fahrenheit sized degrees.

Absolute temperature It was observed that as a gas was cooled that the volume decreased in a regular manner such that, if the process were continued, the volume would go to zero at about -273° C. Thus it was conceived that this would be the lowest possible temperature since all movement would cease at this temperature. This temperature was called absolute zero. A more accurate value is -273.15° C. Lord Kelvin devised a temperature scale based on the Celcius degree that began from absolute zero. The scale is named after him. In the Kelvin scale water freezes at 273.15 Kelvin or 273.15K. The scale has the property that 100K is twice as hot as 50K. This is not true of the Celcius or Fahrenheit scale. The so-called standard temperature of 25° C is 298.15K. The "absolute" property of the Kelvin scale makes the writing of thermodynamic functions simpler.

Chemistry Safety Quiz 1 of 18 1Whom should you call in case of an emergency in the lab? A. B. C. D.

Instructor Nobody A friend Anybody

2.Why is smoking not permitted in the lab? A. B. C. D.

It is inconvenient It is bad for your health The lab could be blown up There are no ash trays in the lab

3.What would immediately be used if your clothing caught fire or if a large chemical spill had occured on your clothing? A. B. C. D.

Fire extinguisher Safety shower Laboratory sinks Eye-wash fountain

What should be worn in a laboratory at all times to decrease the likelihood of eye injury? A. Corrective lenses B. Safety Glasses

C. A mask D. Nothing What should be done if a chemical gets in the eye? A. B. C. D.

Notify the Instructor; then use the eye-wash fountain Use the eye-wash fountain; then return to the experiment Use the eye-wash fountain; then notify the instructor Nothing, unless the chemical causes discomfort

Why is it not advisable to wear contact lenses in the lab? A. B. C. D.

Lenses could inadvertently fall out of the eye Chemical vapor could become trapped between the lenses and the eye Chemical vapor could literally react with the lenses All of the above

What should be done if a chemical gets in the eye? A. B. C. D.

Notify the Instructor; then use the eye-wash fountain Use the eye-wash fountain; then return to the experiment Use the eye-wash fountain; then notify the instructor Nothing, unless the chemical causes discomfort

Describe the procedure used to operate a fire extinguisher. A. Remove pin from handle; Squeeze handle B. Aim extinguisher hose (if any) at base of fire; Squeeze handle C. Remove pin from handle; Aim extinguisher hose (if any) at base of fire; Squeeze handle D. Any of the above choices How can a small contained fire be extinguished most easily? A. B. C. D.

Use a fire extinguisher Use water Call the instructor Smother the fire with a small container (i.e., a beaker)

What precautions are needed with long hair and beards? A. Keep long hair tied back/keep hair away from flames

B. Must be shampooed C. No long hair and/or beards allowed in the lab D. No precautions are necessary What type of footwear is required in the lab? A. B. C. D.

Shoes are optional Hard-soled, covered shoes Sandals Something in a low heel

Eating and drinking is not permitted in the lab because: A. B. C. D.

There would not be enough time to finish the experiment The storeroom serves terrible appetizers You could be poisoned The lab would become quite messy with this type of activity

Are there any conditions under which a student may work alone? A. B. C. D.

Yes No Maybe Students may work unrestricted, at their own convenience

Why are no unauthorized experiments permitted in the lab? A. B. C. D.

The student lacks experience in the lab Most professors love to see only their selected experiments performed The stockroom may not have the reagents that you need It may take more time to perform than expected

What should be the very last function performed in the lab before you leave? A. B. C. D.

Bid the instructor farewell Make sure that your locker is secure Wash your hands Arrange a time with your lab partner for lunch

Describe the procedure for smelling a chemical. A. Stick your nose close to the vessel and breath deeply

B. Point vessel away from face while gently fanning vapors toward nose C. Never smell a chemical D. Smell chemical as you would anything else The safety equipment pictured here is: A. B. C. D.

Safety Blankets Fire Extinguishers Fume Hoods First Aid Kits

The safety equipment pictured here is: A. B. C. D.

Safety Blankets First Aid Kits Fire Alarms Eye-wash Fountains

The safety equipment pictured here is: A. Sodium Bicarbonate

B. Fire Doors C. Safety Showers D. Nothing