# 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 im 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 dont 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 eqution 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

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