What mass of Mg(OH)_2Mg(OH)2 is produced when 100 mL of 0.42 M Mg(NO_3)_2Mg(NO3)2 is added to excess NaOHNaOH solution?

1 Answer
Feb 19, 2017

Mole ratio for the reaction

Mg(NO3)_2 + 2NaOH = 2NaNO_3 + Mg(OH)_2Mg(NO3)2+2NaOH=2NaNO3+Mg(OH)2

1 : 2 :: 2 : 1

For this we need to calculate number of moles in 100ml
of 0.42 M

100/1000 * 0.42 = 0.04210010000.42=0.042

0.042 : 0.042*2 :: 0.042 *2 : 0.0420.042:0.0422::0.0422:0.042

0.042mol Mg(NO3)_2 : "0.084molNaOH" :: "0.084mol "NaNO_3 : 0.042mol Mg(OH)_2"0.042molMg(NO3)2:0.084molNaOH::0.084mol NaNO3:0.042molMg(OH)2

0.042 moles of Mg(OH)_2Mg(OH)2 are formed

"Mass" = "molar mass" xx "moles"Mass=molar mass×moles

Molar mass of Mg(OH)_2Mg(OH)2 = 58.3197

Mass of Mg(OH)_2Mg(OH)2 formed = 58.3197 xx 0.04258.3197×0.042

2.4494274grams of Mg(OH)_2Mg(OH)2