We know 1 mole of any atom or molecules contains 
atom or molecules.
1 mole of HBr i.e 81 gm/mol contains atom or molecules.
So, mass of 
molecules is :
Therefore, mass of molecules is 1.21 gm .
Hence, this is the required solution.
Answer:
D
Explanation:
As you move down anything, towards the earth, (gravitational) potential energy decreases. This eliminates options B and C.
By the law of conservation of energy, the energy of the system stays the same. However the energy may be converted into different forms. In this case, the potential energy is converted into kinetic energy - this is what makes people move faster as they go down the slope. This makes option A wrong and option D right.
Answer:
D) N2O5
Explanation:
The molar mass of a substance is defined as the mass of this substance in 1 mol. To solve this question we must find the molar mass of each option:
<em>Molar mass NO:</em>
1N = 14g/mol*1
1O = 16g/mol*1
14+16 = 30g/mol
<em>Molar mass NO2:</em>
1N = 14g/mol*1
2O = 16g/mol*2
14+32 = 46g/mol
<em>Molar mass N2O:</em>
2N = 14g/mol*2
1O = 16g/mol*1
28+16 = 44g/mol
<em>Molar mass N2O5:</em>
2N = 14g/mol*2
5O = 16g/mol*5
28+80 = 108g/mol
That means the compound with the greatest mass is:
<h3>D) N2O5</h3>
I did this when I was younger
