Online Chem Homework Need Help?

[wakeley58]

Online Chem Homework Need Help I did it and I got 18 wrong and I can do it as many times as i want I was wondering if someone could help me out thanks!

1.Which of the following represents the most energy?
A) A gallon of gasoline
B) A glow stick
C) A hot pack
D) A mole of candy bars
2.
Catalysts increase a reaction rate by
A) increasing the entropy.
B) decreasing the heat of reaction.
C) lowering the activation energy.
D) changing the energy of the reactants.

3.
Which of the following illustrates the second law of thermodynamics?
A) A stitch in time saves nine.
B) The early bird catches the worm.
C) An apple a day keeps the doctor away.
D) A penny saved is a penny earned.

4.
An ice cream sundae contains 540 Calories. Approximately how many calories is this?
A) 540,000 calories
B) 540 calories
C) 0.540 calories
D) 2,300 calories
E) 129,000 calories
5.
With respect to whether a chemical reaction will proceed spontaneously, which of the following is true?
A) The reaction must be exothermic.
B) The reaction must be endothermic.
C) The products must have greater disorder than the reactants.
D) Both heat and disorder must be considered.
6.
The combustion of 6.50 moles of CH4 releases 5,220 kJ of energy. How much energy is produced from the combustion of 15.5 moles of CH4?
A) 12,400 kJ
B) 5,220 kJ
C) 2,190 kJ
D) 0.00297 kJ
E) 526,000 kJ
7.
An 8-oz bottle of mango smoothie reports 150 Cal per serving with 2 servings per container. How many Calories do you consume on drinking the whole bottle?
A) 75 Cal
B) 100 Cal
C) 150 Cal
D) 300 Cal
8.
The combustion of 1 mol CH4 releases 803 kJ of energy. This reaction is
A) fast.
B) exothermic.
C) endothermic.
D) cold.
9.
The photosynthesis reaction is catalyzed by enzymes. How does this affect the reaction?
A) The reaction becomes thermodynamically favorable.
B) The reaction becomes more efficient.
C) The activation energy decreases.
D) The products become more stable.
10.
Increasing the temperature of a swimming pool causes the water molecules to
A) hydrogen bond more.
B) collide less frequently.
C) move around faster.
D) react with O2 in the atmosphere.
11.
After you eat lunch, your body metabolizes the food to form ATP. Later that afternoon, you go for a run, powered by ATP. What is true about this process?
A) Potential energy in food is transformed to chemical energy that can be used to power work.
B) Because energy is conserved, all the energy is trapped during each transformation with no loss to the surroundings.
C) Kinetic energy is transformed to potential energy.
D) These transformations are far less efficient than those that occur in an internal combustion engine, which operates at almost 100% efficiency.

12.
The decomposition of 2 mol of water to hydrogen and oxygen requires 573 kJ of energy. The reaction of hydrogen and oxygen to form 4 mol of water
A) requires 573 kJ of energy.
B) releases 573 kJ of energy.
C) requires 1150 kJ of energy.
D) releases 1150 kJ of energy.
13.
Which of the following should dissolve completely in your cup of coffee the fastest?
A) Powdered sugar
B) Table sugar
C) Sugar cubes
D) A lollipop
14.
A snack bar contains 220 Cal. How many joules is this?
A) 53 J
B) 920 J
C) 220 J
D) 920,000 J
15.
Carbon dioxide and water are converted to sugar and oxygen in the following reaction:

Which of the following is true of this reaction?
A) Entropy increases because there are more moles of products than reactants.
B) Entropy decreases because there are fewer moles of products than reactants.
C) This reaction is exothermic.
D) This reaction is spontaneous under all conditions.

16.
What is the consequence of a reaction that has a high activation energy?
A) The reaction will be slow.
B) The reaction will be endothermic.
C) The reaction will favor the products.
D) The reaction will release energy.
17.
Assume that burning a load of wood releases about 50,000 calories. If you have a pot containing 1000 g of water on the woodstove, how much could the temperature rise?
A) About 50°C
B) About 100°C
C) About 500°C
D) About 5000°C
18.
Power plants are about ~40% efficient at converting a fuel's energy into electricity delivered to the home. What law of chemistry governs this phenomenon?
A) Like dissolves like.
B) Conservation of energy
C) Conservation of matter
D) The second law of thermodynamics

19.
A snack bar contains 220 Cal. How many calories is this?
A) 0.220 cal
B) 220,000 cal
C) 220 cal
D) 920 cal About 5000°C
20.
Assume that burning a quantity of wood releases about 500,000 calories. If you have a pot containing 4,000 grams of water, by how much could the temperature rise? (specific heat for water is 1.00 cal/g?oC)
A) about 125 oC
B) about 8 oC
C) about 1,250 oC
D) about 250oC
E) about 12,500 oC