Do electric or magnetic fields affect the x-rays?

Combustion analysis of 0.300 g of an unknown compound containing carbon, hydrogen, and oxygen produced 0.5213 g of co2 and 0.283

Lyrx [107]

First, we have to get how many grams of C & H & O in the compound:
- the mass of C on CO2 = mass of CO2*molar mass of C /molar mass of CO2
= 0.5213 * 12 / 44 = 0.142 g
- the mass of H atom on H2O = mass of H2O*molar mass of H / molar mass of H2O
=0.2835 * 2 / 18 = 0.0315 g
- the mass of O = the total mass - the mass of C atom - the mass of H atom
= 0.3 - 0.142 - 0.0315 = 0.1265 g
Convert the mass to mole by divided by molar mass
C(0.142/12) H(0.0315/2) O(0.1265/16)
C(0.0118) H(0.01575) O(0.0079) by dividing by the smallest value 0.0079
C1.504 H3.99 O1 by rounding to the nearst fraction
C3/2 H4/1 )1/1 multiply by 2
∴ the emprical formula C3H8O2

6 0

2 years ago

Calculate the number of grams of oxygen gas in a 24L container at STP

romanna [79]

There are 34 g of oxygen in the container.

We can use the<em> Ideal Gas Law</em> to solve this problem.

$pV = nRT$

But $n = \frac{m}{M}$ , so

$pV = \frac{m}{M}RT$ and

$m = \frac{pVM}{RT}\\$

STP is 0 °C and 1 bar, so

$m = \frac{\text{1 bar} \times \text{24 L} \times 32.00 \text{ g}\cdot\text{mol}^{-1}}{\text{0.083 14 } \text{bar}\cdot\text{L}\cdot\text{K}^{-1}\text{mol}^{-1}\times\text{273.15 K} } = \textbf{34 g}\\$

7 0

3 years ago

Lab: Calorimetry and Specific Heat

gayaneshka [121]

Answer:

Title for the lab--->Calorimetry and Specific Heat

Name:

Teacher:

Date:

Purpose: Explore how the specific heat of a substance can be determined using a “coffee cup” calorimeter.

Question: How can you determine the specific heat of a metal using a calorimeter?

Hypothesis: If a metal has a low specific heat, then the metal could make an excellent material for cookware because it takes less heat to raise the temperature of the metal to cook food.

MATERIALS:

- Two polystyrene coffee cups

- Lid for polystyrene cup

- Thermometer

- 250 mL beaker

- 400 mL beaker

- Ring stand

- Two buret clamps

- Hot plate

- Test-tube holder

- 50 mL graduated cylinder

- Water

- aluminum, copper, iron, and lead powder

- Analytical balance

PROCEDURE:

1) Set up a 600 mL beaker and add 400 mL of dis"lled water inside and place it on a hot plate un"l it boils. Also set up 2 dry Styrofoam cups with a lid aside and add 100.0 mL tap water (calorimeter water) inside.

2) In the boiling water, place the unknown metal sample inside for about 30 min. Before though, weigh it accurately and record the mass on your data sheet.

3) After 30 min, take the temperature of boiling water to the nearest 0.1 °C (Ini"al temp of metal), then take the metal out of the boiling water and replace it into Styrofoam cups filled with room temperature tap water. Ini"al temperature of water is the room temperature of the tap water.

4) Take every 15 seconds for about 2 minutes the temperature of water inside the calorimeter with a thermometer inserted through the hole in the lid. Gently swirl the cup to mix the contents and record the temperature. Use the highest temperature.

5) Calculate the specific heat of the metal sample.

then the table will be in the picture i posted on here

next is your ---> Analysis /Conclusion

Analysis:

Analyzed from the data above, we know the temperature that is measured depends on the amount of mole in the solution. If the amount of mole in the solution is large, the temperature will be as well. After a few moments, the temperature rises and falls, and in some instances, it remains steady.

Conclusion:

In conclusion, I do believe my hypothesis was supported through my experiments. Through said experiments, I identified the unknown metal as we calculated the changes in the heat, and found that the metals that should be put to use are copper and iron metals. Copper and iron have a low specific heat, which makes these ideal metals when creating cookware. When a metal has low specific heat, it needs less energy to produce heat and it cools down with less energy as well. For these reasons, my hypothesis is supported.

Explanation:

hope this helps :)

5 0

2 years ago

Regarding chemical elements such as argon that are inert, which of the following statements is true?

QveST [7]

Answer:

C. They don't react with other elements to form compounds

Explanation:

The elements in Group 18 of the periodic table are called "inert", or noble gases.

These elements have their valence shell (the outermost shell of the atom) full of electrons, so they do not gain/give off electrons, and therefore, they do not react with other elements, so they do not form compounds.

In fact, normally the elements try to gain/give off electrons in order to fullfill their outermost shell (the valence shell). For instance, an atom that has 1 electron only in its valence shell, try to "give away" this electron in order to have its outermost shell completed. On the other hand, an atom which has 7 electrons in its valence shell tries to "gain" one electron in order to fullfill the valence shell.

Noble gases, instead, have already 8 electrons in their valence shell, so their valence shell is already completed, therefore they do not react with other elements, and therefore they are called "inert".

4 0

2 years ago

The value of K at constant temperature depends on the amounts of reactants and products that are mixed together initially. A lar

Verdich [7]

Answer:

a) K = [ CO2(g) ]

⇒ the [ CaCO3(s) ] does not appear in the denominator of the equilibrium constant, as it is a pure solid substance.

b) Kp = K (RT)∧Δn

⇒ the values of K and Kp are not the same

c) K >> 1, The reaction has a high yield and is said to be shifted to the right. then the rate of the forward reaction is greater than the rate of the reverse reaction at equilibrium.

Explanation:

a) CaCO3(s) ↔ CaO(s) + CO2(g)

⇒ K = [ CO2(g) ]

∴ the [ CaCO3(s) ] does not appear in the denominator of the equilibrium constant, as it is a pure solid substance.

b) H2(g) + F2(g) ↔ 2 HF(g)

⇒ K = [ HF(g) ] ² / [ F2(g) ] * [ H2(g) ]

⇒ Kp = PHF² / PF2 * PH2

for ideal gas:

PV = RTn

⇒ P = n/V RT = [ ] RT

⇒ Kp = K (RT)∧Δn

⇒ the values of K and Kp are not the same.

c) K >> 1, The reaction has a high yield and is said to be shifted to the right. then the rate of the forward reaction is greater than the rate of the reverse reaction at equilibrium.

8 0

2 years ago