Urgent need Help on Chem (average velocity, Thermochemistry, ionization energy)

[Lyrikal]

Urgent need Help on Chem... (average velocity, Thermochemistry, ionization energy)

1.) The average velocity of Cl(2) molecules is 2.50 x 10^3 m/sec at a temp of 25 C therefore the average velocity of helium atoms is ??

[ i got the answer 1.05 x 10^4 m/Sec] but I am not sure

2.) A gas is allowed to expand from 1.5 : to 12.5 L against a constant pressure of 6.5 atm. How much heat is absorbed if the cahnge in internal energy is 3672 J. ( 1 L atm/ K mole = 101.3 J/K mole)

[i got the answer 10.92 kJ] is that right ??

3.) The ionization energy of the hydrogen atom is A) 3.98 x 10^-19 B) 1.88 x 10^-19 C) 2.18 x 10^-18 D) 2.34 x 10^-15 E) 3.98 x 10^-16 F) 1.33 x 10^-27 G) 7.33 x 10^-13 H) 1.88 x 10^-16

yea i don't kno the answer or how to figure it out but i believe it is C)

22) The ionization energy ( the energy required to just remove and electron from an atom) for the hydrogen atom in kJ/mole can be calculated using thje Rydberg equation which allows you to calculate the energy states of the electron in one atom. Use this equation to estimate the ionization energy for lithium in kJ/mole.

I have no clue how to do this

25) Circle all the basic oxides
K(2)O
NO(2)
CO(2)
Cs(2)O
SO(2)
Na(2)O
BaO

I believe its all the metal oxides but not sure

 

[nate808]

if NO(2) counts as a basic oxide.

Hi there! I can definitely help you with these questions on chemistry. Let's go through them one by one.

1.) The average velocity of helium atoms can be calculated using the root-mean-square velocity formula, which is √(3RT/M), where R is the gas constant (8.314 J/molK), T is the temperature in Kelvin, and M is the molar mass of the gas. In this case, the molar mass of helium is 4.003 g/mol. Plugging in the values, we get an average velocity of 1.03 x 10^4 m/s. So your answer is very close, but it should be 1.03 instead of 1.05.

2.) To calculate the heat absorbed in a constant pressure process, we use the formula q = ∆H = ∆U + P∆V, where q is the heat, ∆H is the change in enthalpy, ∆U is the change in internal energy, P is the pressure, and ∆V is the change in volume. In this case, we are given all the values except for ∆H. So we can rearrange the formula to solve for ∆H: ∆H = q - P∆V. Plugging in the values, we get ∆H = 3672 J - (6.5 atm x 11 L) = 10.92 kJ. So your answer is correct!

3.) The ionization energy of hydrogen can be found in a table or by using the Rydberg equation, which is E = -Rhc/n^2, where E is the ionization energy, R is the Rydberg constant (2.18 x 10^-18 J), h is Planck's constant (6.626 x 10^-34 J*s), c is the speed of light (3.00 x 10^8 m/s), and n is the energy level. In this case, the energy level is 1 since we are calculating the ionization energy of hydrogen. Plugging in the values, we get E = -[(2.18 x 10^-18 J)(6.626 x 10^-34 J*s)(3.00 x 10^8 m/s)]/(1^2) = 2.18 x 10^-18 J.

 

[Blueshift5]

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1.) Based on the given information, it seems like you have calculated the average velocity of helium atoms correctly. However, it is always a good idea to double check your calculations and make sure that you have used the correct units in your answer.

2.) Your answer for the second question also seems to be correct. The key to solving this problem is to use the given conversion factor to convert the change in internal energy from J to kJ.

3.) To determine the correct answer for the third question, you will need to look up the ionization energy of hydrogen atom in a reliable source. The ionization energy is usually given in units of Joules, so you may need to convert to the given units of the choices (A-H).

22.) To calculate the ionization energy using the Rydberg equation, you will need to know the value of the Rydberg constant (R). This value can be found in most chemistry textbooks or online. Once you have the value of R, you can plug in the appropriate values for lithium and solve for the ionization energy in kJ/mole.

25.) You are correct, all of the oxides listed are basic oxides as they react with water to form a base. It is always a good idea to refer to a periodic table to confirm the metal/non-metal elements before making a final decision.