Calculate the cost of one pound of nitrogen from a fertilizer containing 30.0 % sodium nitrate by weight and costing $9.00 per 100 lb. Express your answer in dollars per pound of nitrogen to three significant figures.

Respuesta :

Answer:

1.82 lb

Explanation:

Given that:

The chemical formula for sodium nitrate is NaNO₃, thus its molar mass = 84.99 g/mole

Also, the atomic mass of Nitrogen (N) = 14 g/mole

Thus; the mass of N in NaNO₃ = (14/84.99) × 100

the mass of N in NaNaNO₃ = 16.473 %

The cost of the fertilizer = $9.00/100 lb

Hence, for one pound of Nitrogen(N) from the fertilizer containing NaNO₃; we have:

= 100/16.473 lb of NaNO₃

= 6.0705 lb of NaNO₃

Given that the fertilizer contains 30% of NaNO₃

The needed amount of fertilizer =  6.0705 × (100/30)

The needed amount of fertilizer =20.235  lb

Thus the cost of one pound of nitrogen from the fertilizer is:

= ( $9.00/100 lb ) × 20.235  lb

= 1.82 lb

Lanuel

To calculate the cost of one pound of nitrogen from this fertilizer is $1.82

Given the following data:

  • Percent by mass of [tex]NaNo_3[/tex] = 30%
  • Cost of [tex]NaNo_3[/tex] = $9.00 per 100 lb.

Note: Sodium nitrate = [tex]NaNo_3[/tex]

Molar mass of [tex]NaNo_3[/tex]  = 84.99 g/mol.

Atomic mass of nitrogen (N) = 14.00 g/mol.

To calculate the cost of one pound of nitrogen from this fertilizer:

First of all, we would determine the mass of nitrogen contained in sodium nitrate.

[tex]Mass \;of \;N = \frac{14}{84.99} \times 100\\\\Mass \;of \;N = \frac{1400}{84.99}[/tex]

Mass of N = 16.47 grams.

Next, we would find a pound of nitrogen in the fertilizer:

[tex]One\; pound \;of\;N = \frac{100}{16.47}[/tex]

One pound of nitrogen = 6.07 lb of [tex]NaNo_3[/tex]

Also, we would calculate the amount of nitrogen in [tex]NaNo_3[/tex] required from the fertilizer.

[tex]Amount \;of\;N = \frac{100}{30} \times 6.07\\\\Amount \;of\;N = \frac{607}{30} \\\\Amount \;of\;N = 20.2\;lb[/tex]

Now, we can calculate the cost of one pound of nitrogen from this fertilizer:

[tex]Cost = \frac{9.00}{100} \times 20.2\\\\Cost = \frac{181.8}{100} \\\\Cost = 1.818[/tex]

To three significant figures:

Cost = $1.82

Read more: https://brainly.com/question/16906167