Answer to Question #175443 in Inorganic Chemistry for Naftal

Question

[B2(OH)4(O2)2]2-. Sodium perborate has the empirical formula NaBO3.4H2O,

Dissolve 4.77 g of sodium tetraborate decahydrate (borax) and 1.0 g of NaOH in 30 ml distilled water. Cool the solution in ice and slowly add 5.6 g of 30 % H2O2 solution. Sodium perborate will slowly begin to crystallise. Suction filter the cold solution rapidly through a filter pater. Retain the filtrate to see if further crystallisation occurs. Repeat filtration if further crystallization occurs, and combine the solids. Wash the product with cold distilled water and then with ethanol and finally with a small quantity of diethyl ether. Allow to air dry on a filter paper and determine the yield.

Post lab questions

• Write a balanced reaction equation for the preparation of the product. Na2B4O7.10H2O + ___H2O2 + __NaOH + ____H2O products

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• Starting with 4.77 g of borax, determine the theoretical yield. From your experimental yield, calculate the percentage yield. Actual yield is 5.4809g

Answer 1

$Na_2B_4O_7.10H_2O+4H_2O_2+2NaOH+H_2O\to 2Na_2(B_2(O_2)_2)_2(OH)_4).6H_2O$

Theoritical yield =83%

Percentage yield =53.47%