The Grass Doctor

stuck on a chemistry question?

Plz i do not want an answer i just want a guide im stuck on how 2 do this question A lawn fertilizer is rated as 6.00% nitrogen, meaning 6.00 g of N in 100. g of fertilizer. The nitrogen is present in the form of urea, (NH2)2CO. How many grams of urea are present in 153 g of the fertilizer to supply the rated amount of nitrogen?

Public Comments

1. First find the proportion of N in your compound, (NH2)2CO has 2 Nitrogen molecules 4 Hydrogen molecules 1 Carbon molecule and 1 Oxygen molecule. So you add up there molecular weights 2(14)+4(1)+1(12)+1(16)=60 then you take the mass of your Nitrogen in the compound which is 28 and divide it by the formula weight to learn that your compound is 46.67% Nitrogen then you take your 153g of fertilizer and times it times your amount of nitrogen that should be in it 153x0.06=9.18g you take this 9.18g times the percentage of nitrogen in your compound 9.18g x 0.4667= 19.67g of urea
2. There's 6*(153/100)=9,18 g of N in 153 g of fetilizer There's 9,18 g of N in 9,18*(60/28)=19,67 g of (NH2)CO