<span>128 g/mol
Using Graham's law of effusion we have the formula:
r1/r2 = sqrt(m2/m1)
where
r1 = rate of effusion for gas 1
r2 = rate of effusion for gas 2
m1 = molar mass of gas 1
m2 = molar mass of gas 2
Since the atomic weight of oxygen is 15.999, the molar mass for O2 = 2 * 15.999 = 31.998
Now let's subsitute the known values into Graham's equation and solve for m2.
r1/r2 = sqrt(m2/m1)
2/1 = sqrt(m2/31.998)
4/1 = m2/31.998
127.992 = m2
So the molar mass of the unknown gas is 127.992 g/mol.
Rounding to 3 significant figures gives 128 g/mol</span>
Answer:
we will except an increase in the polarity of the system and this will cause the Non-polar spot to be near the solvent front, while the polar spot will run at an approximate speed of 0.5 Rf
Explanation:
when we run a TLC plate in a 50/50 mixture of hexanes and ethyl acetate we will except an increase in the polarity of the system and this will cause the Non-polar spot to be near the solvent front, while the polar spot will run at an approximate speed of 0.5 Rf
The speed of the polar spot depends largely on the level of polarity, an increase in the polarity will see both spots of Neat hexane run when we run a TLC plate in a 50/50 mixture of hexanes and ethyl acetate
Answer: Option (e) is the correct answer.
Explanation:
A bond that is formed when an electron is transferred from one atom to another results in the formation of an ionic bond.
For example, NaBr will be an ionic compound as there is transfer of electron from Na to Br.
Whereas a bond that is formed by sharing of electrons is known as a covalent bond.
For example,
will be a covalent compound as there is sharing of electron between carbon and bromine atom.
Also, when electrons are shared between the combining atoms and there is large difference in electronegativity of these atoms then partial charges develop on these atoms. As a result, it forms a polar covalent bond.
For example, in a HBr compound there is sharing of electrons between H and Br. Also, due to difference in electronegativity there will be partial positive charge on H and partial negative charge on Br.
Thus, we can conclude that out of the given options HBr is the only compound that has polar covalent bonds.
Answer:
A. Move the buret clamp to a ring stand with a larger base.
Explanation:
The ring stands are used to hold burettes, light in weight to avoid loss of stability, that is why it is necessary to change the size of the ring stand so that it can support the buret that we are going to use. It is not recommended to balance it with the hand since it would give us an inaccurate result in the titration.