Answer: 250 ml of stock solution with molarity of 12.0 M is measured using a pipette and 250 ml of water is added to volumetric flask of 500 ml to make the final volume of 500 ml.
Explanation:
According to the dilution law,

where,
= concentration of stock solution = 12.0 M
= volume of stock solution = ?
= concentration of diluted solution= 6.00 M
= volume of diluted acid solution = 500 ml
Putting in the values we get:


Thus 250 ml of stock solution with molarity of 12.0 M is measured using a pipette and 250 ml of water is added to volumetric flask of 500 ml to make the final volume of 500 ml.
Answer:
C. 
Explanation:
Molecules with the stronger intermolecular forces are pulled tightly together to form solid at higher temperatures and that's why the freezing point is higher.
Also, molecules with the stronger intermolecular force have greater interaction between the molecules and thus on heating do not boil easily and have high boiling point also.
Thus, melting point and boiling point increases with increase in number of carbon atoms and also increase in intermolecular forces (like hydrogen bonding, if present).
Thus, the compound which is gas at room temperature is
<u>because it has least number of carbon atoms and absence of hydrogen bonding.</u>
<u></u>
To control what molecules go in and out of the cell.