Question

Ammonium hydrogen phosphate, a common fertilizer; is made from reacting phosphoric acid with ammonia, NH3. What mass of ammonia will react with 2800 kg of H3PO4? Please show how you got the answer

Answer 1

H3PO4 + 2 NH3 >> (NH4)2HPO4 
moles NH3 = 10.00/ 17.3052 g/mol = 0.5872 

moles fertilizer = 0.5872 / 2 = 0.2936 

moles H3PO4 = 2800000 g / 98 g/mol = 28571 
moles NH3 = 2 x 28571 =57142 
mass NH3 = 57142 x 17.3052 = 988853 g => 989 Kg

Answer 2

Answer: 971.428 kg of ammonia will react with 2800 kg of phosphoric acid.

Explanation:

Mass of sodium hydrogen carbonate in 1 tablet =2800 kg = 2,800,000 g

$H_3PO_4+ 2NH_3\rightarrow (NH_4)_2HPO_4$

Moles of $H_3PO_4=\frac{\text{Mass of }H_3PO_4}{\text{Molar Mass of }H_3PO_4}=\frac{2,800,000 g}{98 g/mol}=28,571.42 moles$

According to reaction 1 mole of$]H_3PO_4$ reacts with 2 mole of $NH_3$ then 28,571.42 mole of$H_3PO_4$ will react with: $\frac{2}{1}\times 28,571.42$ moles of $NH_3$ that is 57,142.84 moles.

Mass of $NH_3=17 g/mol\times 57,142.84 moles.=971,428.28 g=971.428 kg$

971.428 kg of ammonia will react with 2800 kg of phosphoric acid.