1) How many grams of PbCl2 are formed when 25

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1) How many grams of PbCl2 are formed when 25.0 mL of 0.654 M KCl react with Pb(NO3)2? 

2KCl(aq) + Pb(NO3) 2(aq) → 2KNO3(aq) + PbCl2(s) Answer= 2.27 g

I WAS SHOWN TO DO IT AS PRESENTED BELOW: PLEASE SHOW ME A SIMPLE, MORE STRAIGHT FORWARD WAY TO DO THE MATH, I AM NOT UNDERSTANDING THIS WAY. ALSO NOT SURE WHERE THE 10^3 CAME FROM?

 moles of KCl= Molarity×volume in L

Moles= 0.654M×(25.0/1000)L=0.01635 moles

2KCl(aq) + Pb(NO3) 2(aq) → 2KNO3(aq) + PbCl2(s)

From the balanced equation, mole ratio of KCl: PbCl2=2:1

Moles of PbCl2= 0.01635 moles/2=8.175× 10^-3moles

Moles=mass in g/RFM

RFM for PbCl2=278g/mol

Mass in g=moles ×RFM

Mass in g=8.175× 10^-3moles×278g/mol (WHEN I CALC THIS IT EQUALS 22.7?)

Mass in g=2.27g

2) The equilibrium constant for the formation of ammonia (NH3) from nitrogen and hydrogen is 1.6 × 102. What is the form of the equilibrium constant? (Hint: balance the reaction!)