Answer:
12.7mol Na.
Explanation:
Hello there!
In this case, according to the concept of mole, which stands for the amount of substance, we can recall the concept of Avogadro's number whereby we understand that one mole of any substance contains 6.022x10²³ particles, for the given atoms of sodium, we can calculate the moles as shown below:

Thus, by performing the division we obtain:

Regards!
Speed
Explanation:
The distance travelled by a body per unit time
Capillary action is defined as the ability of a liquid to go up a narrow space without the help or opposition of external forces. One of the most important factors affecting capillary action is the intermolecular forces within a substance. The higher the IMF, the greater the capillary action. The H-bonding in water gives it greater IMF than acetone, so water has greater capillary action.
Answer : The mass of nitric acid is, 214.234 grams.
Solution : Given,
Moles of nitric acid = 3.4 moles
Molar mass of nitric acid = 63.01 g/mole
Formula used :

Now put all the given values in this formula, we get the mass of nitric acid.

Therefore, the mass of nitric acid is, 214.234 grams.
Assuming the question is asking for percent composition by mass,
The molar mass of sodium bicarbonate is:
22.990 + 1.008 + 12.011 + 3*15.999 = 84.006 g/mol
The molar mass of 3 oxygen atoms is:
3*15.999 = 47.997 g/mol
The percentage composition by mass is:
47.997/84.006 * 100% = 57.1% (3 s.f.)