The chemical formula of aspirin is C9H8O4. What is the mass of 0.40 mol
of aspirin?​

Explanation:

To convert from moles to grams, we must use the molar mass (also known as the gram formula mass).

First, look up the molar masses of the elements in the formula.

Next, multiply by the subscript, because it tells us the number of atoms of each element in the formula.

Add the values.

Use this molar mass as a ratio.

Multiply by the given number of moles, 0.40

The units moles of aspirin cancel.

The original number of moles has 2 sig figs (4 and 0), so answer must have the same. For the number we calculated, it is the ones place. The 0 in the tenth place tells us to leave the 2.

the equation that correctly represent the reaction for formation of ammonia is

n2+ 3h2 → 2nh3 (answer d)

1 mole of nitrogen gas (n2) react with 3 moles of hydrogen gas (h2) to form 2 moles of ammonia ( nh3). this is in a process known as haber process were iron is used as a catalyst and reaction take place that a higher temperature and pressure. the process is exothermic hence energy is released.