OMG, I did the other fifteen questions of my homework but I'm stuck on these.
#1: Which has the higher average kinetic energy, a tub full of 50'C water, or a small cup of 52'C water. Why?
Which has more total kinetic energy, the tub or the cup? Why?
#2: Lithium, sodium, and potassium all react violently with water. Knowing this, and looking at the periodic table, would you expect cesium to react violently with water as well? Explain why or why not?
#3: What is a periodic trend?
Using the concept of periodic trend, which is larger in size: an atom of cesium (Cs) or an atom of astatine (At)?
#4: You hold a potato chip motionless in your hand above the ground.
What kind of energy does the potato chip have based on its position?
You drop the potato chip. What kind of energy does it have as it falls?
How would you release the chemical potential energy inside the potato chip?
The potato chip has 10,000 calories of chemical potential energy. How many joules does it have?
#5: You have an irregularly shaped rock. How can you find its volume?
You discover that the volume of the material is 150 mL. Its mass is is 1701g. What is its density?
We will be happy to critique your thinking.
Eh, sorry. ^^;
I'm really bad at chemistry.
#1: (I don't get the first part) The cup because the water is higher in temperature.
#2: No, it is very soluble in water
#3: They are the tendencies of certain elemental characteristics to increase or decrease as one progresses from one corner of the Periodic table of elements.
#4: (I really don't understand this...??????????)
#5: ( Nor do I get this one. )
1. the cup has higher temp, and temp is a measure of average KE. The tub has more heat energy (more mass).
2. Your answer is not logical, the question is about reactivity. Cs is the most reactive of all metals.
3. Not exactly. Look this up in the text, and see the trends on atomic size to answer the At question.
4. Kinetic energy is the energy of moving. To get the chem energy, you could burn it. 1joule=4.1calories
5. Look up the term displacement in your text. Density = mass/volume
If you are serious on not understanding these elementary concepts, you need a tutor , or drop chemistry.
Well I just started Chemistry...Monday. I'm home-schooled and only have teachers from nine in the morning to noon. And I payed $50 for this course.
Okay, I'll re-read the chapter to see if I understand anything.
On hot days, you may have noticed that potato chip bags seem to “inflate”, even though they have not been opened. If I have a 250 mL bag at a temperature of 19 0C, and I leave it in my car, which has a temperature of 600 C, what will the new volume be?
#1: To determine which has the higher average kinetic energy between the tub of 50°C water and the small cup of 52°C water, we need to understand that the average kinetic energy of atoms or molecules increases with temperature. The formula for average kinetic energy is given by KE_avg = (3/2)kT, where k is the Boltzmann constant and T is the temperature in Kelvin.
First, we need to convert the temperatures from Celsius to Kelvin. To do this, we add 273.15 to the Celsius temperatures. So, the tub's temperature is 50°C + 273.15 = 323.15 K, and the cup's temperature is 52°C + 273.15 = 325.15 K.
Comparing the temperatures, we find that the cup has a higher temperature, which means it has a higher average kinetic energy.
Now, let's discuss the total kinetic energy. The total kinetic energy of an object is directly proportional to its mass and the square of its velocity. Since the question does not provide any information about the velocity of the water, we cannot determine which has more total kinetic energy.
#2: To determine whether cesium would react violently with water, we can refer to the periodic table. Lithium, sodium, and potassium, being in the same group as cesium (Group 1), react violently with water. Group 1 elements are alkali metals, which are highly reactive with water due to their low ionization energy.
Based on this trend, we would expect cesium to react violently with water as well. However, it is important to note that the reactivity of elements can sometimes depend on specific conditions and factors.
#3: A periodic trend refers to the pattern or trend that exists in the properties of elements as you move across or down the periodic table. These trends are observed in various properties such as atomic radius, ionization energy, electronegativity, etc.
For example, the atomic radius generally increases as you move down a group (from top to bottom) and decreases as you move across a period (from left to right). This trend can be explained by the increasing number of energy levels (shells) as you move down a group and the increasing effective nuclear charge as you move across a period.
Using the concept of periodic trend, we can compare the atomic sizes of cesium (Cs) and astatine (At). Since cesium is located in Group 1 and astatine is the last element in Group 17 (Group 7), we can conclude that cesium is larger in size than astatine. This is because the atomic radius generally increases as you move down a group.
#4: Based on its position, the potato chip has potential energy. Specifically, it has gravitational potential energy due to its height above the ground.
When you drop the potato chip, it starts falling towards the ground. As it falls, its potential energy is converted into kinetic energy. The potato chip gains kinetic energy due to its motion.
To release the chemical potential energy inside the potato chip, you would need to chemically react or combust the chip. This would involve breaking down the molecular structures of the chip's components and releasing the stored energy.
To calculate the conversion of calories to joules, we can use the conversion factor: 1 calorie = 4.184 joules. Therefore, the potato chip with 10,000 calories of chemical potential energy would have 10,000 * 4.184 = 41,840 joules of energy.
#5: To find the volume of an irregularly shaped rock, you can use the displacement method.
First, fill a graduated cylinder partially with water and record the initial volume. Make sure to note the water level accurately.
Then, carefully submerge the rock into the water, ensuring that no air bubbles are trapped around it. The water level will rise due to the displacement caused by the rock.
Record the final volume reading, taking into account the accuracy of the water level again. Subtract the initial volume from the final volume to get the volume of the rock.
For the second question, to calculate density, use the formula:
Density = Mass / Volume
Given that the volume is 150 mL and the mass is 1701 g, we substitute these values into the formula:
Density = 1701 g / 150 mL
Since density is typically expressed in grams per milliliter (g/mL), we have our answer.