D. All of the above. Developing medicine, analyzing compounds and producing new product such as plastic all have to deal with chemistry.
The balanced reaction is 3
Ca
(
s
)
+
N
2
(
g
) → Ca
3
N
2
(
s
).
<u>Explanation</u>:
A chemical equation is said to be balanced when the total number of atoms present on the reactants side is equal to the total number of atoms present on the product side.
The unbalanced chemical equation is as follows,
Ca
(
s
)
+
N
2
(
g
) → Ca
3
N
2
(
s
)
To balance this equation, you need to look at how many atoms of each element are present on each side of the chemical equation.
Calcium has 1 atom on the reactant and 3 on the products side. To balance the reaction we need to multiply the calcium atom by 3 on the reactants side.
3
Ca
(
s
)
+
N
2
(
g
) → Ca
3
N
2
(
s
)
Now Nitrogen has a coefficient of 2 on both sides of the reaction. Hence the balanced chemical equation will thus be
3
Ca
(
s
)
+
N
2
(
g
) → Ca
3
N
2
(
s
)
<span>9.40x10^19 molecules.
The balanced equation for ammonia is:
N2 + 3H2 ==> 2NH3
So for every 3 moles of hydrogen gas, 2 moles of ammonia is produced. So let's calculate the molar mass of hydrogen and ammonia, starting with the respective atomic weights:
Atomic weight nitrogen = 14.0067
Atomic weight hydrogen = 1.00794
Molar mass H2 = 2 * 1.00794 = 2.01588 g/mol
Molar mass NH3 = 14.0067 + 3 * 1.00794 = 17.03052 g/mol
Moles H2 = 4.72 x 10^-4 g / 2.01588 g/mol = 2.34140921086573x10^-4 mol
Moles NH3 = 2.34140921086573x10^-4 mol * (2/3) = 1.56094x10^-4 mol
Now to convert from moles to molecules, just multiply by Avogadro's number:
1.56094x10^-4 * 6.0221409x10^23 = 9.400197448261x10^19
Rounding to 3 significant figures gives 9.40x10^19 molecules.</span>
D = m / V
d = 1300 g / 743 cm³
d = 1.749 g/cm³
