Please help ASAP! What mass of hydrogen is needed to produce 10 moles of ammonia (NH3)? N2 +
3H2 → 2NH3
30 moles
30 grams
15 grams
15 moles

Mass = 30 g

Explanation:

Given data:

Mass of hydrogen needed = ?

Number of moles of ammonia produced = 10 mol

Solution:

Chemical equation:

N₂ + 3H₂        →      2NH₃

Now we will compare the moles of ammonia and hydrogen.

                  NH₃            :                H₂

                    2               :                3

                   10               :               3/2×10 = 15 mol

Mass of hydrogen needed:

Mass = number of moles × molar mass

Mass = 15 mol × 2 g/mol

Mass = 30 g

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.