Question

For the reaction З КОН + Н, РО, - к, РО, +3Н,0 how many grams of potassium phosphate, K3PO4, are produced from 86.5 g of potassium hydroxide, KOH? mass of potassium phosphate: TOOLS х10

Answer 1

Molar mass of KOH,

MM = 1*MM(K) + 1*MM(O) + 1*MM(H)

= 1*39.1 + 1*16.0 + 1*1.008

= 56.108 g/mol

mass of KOH = 86.5 g

mol of KOH = (mass)/(molar mass)

= 86.5/56.11

= 1.542 mol

According to balanced equation

mol of K3PO4 formed = (1/3)* moles of KOH

= (1/3)*1.542

= 0.5139 mol

Molar mass of K3PO4,

MM = 3*MM(K) + 1*MM(P) + 4*MM(O)

= 3*39.1 + 1*30.97 + 4*16.0

= 212.27 g/mol

mass of K3PO4 = number of mol * molar mass

= 0.5139*2.123*10^2

= 1.091*10^2 g

Answer: 109 g