The nitrogen in sodium nitr ate and in ammonium sulfate is available to plants as fertilizer. which is the more economical source of nitrogen, a fertilizer containing 30.0% sodium nitrate by weight and costing $9.00 per 100 lb or one containing 20.0% ammonium sulfate by weight and costing $8.10 per 100 lb?

The sodium nitrate is more economical

Explanation:

Hi, to compare this two options you need to determine the amount of nitrogen per 100 lb of both and then estimate its cost:

1) Sodium nitrate

This fertilizer has 30 % by weight of sodium nitrate:

The molecular weight of sodium nitrate:

So, this salt has 14 g of N per 85 g:

Cost per gram:

2) Ammonium sulfate

This fertilizer has 20 % by weight of ammonium sulfate:

The molecular weight of ammonium sulfate:

So, this salt has 14 g of N per 114 g:

Cost per gram: