A 156g sample of sodium bicarbonate NaHCO3 is decomposed by

A 15.6g sample of sodium bicarbonate (NaHCO3) is decomposed by heating. How many grams of Na2CO3 remains? 2NaHCO3 (s)- Na2C03 (s)+ Co2(g)+ H20 8) QUESTION 1 15.60 5.89 9.8g 10.09 QUESTION 2 A 15.6g sample of sodium bicarbonate (NaHCO3) is decomposed by heating. How many combined grams of CO2 and H20 was lost due to heating? 5.8g 12.5g 9.8g 07.52g A 4832g mixture of KCIO3 and NaCI is heated on a hot plate causing the decomposition to form KCI (s) and 02 (g). 1f 3.474 g of the mixture remains after complete decomposition: 2KCIO3 (s) 2KCI (s) + 302 (g). Calculate moles of O2 lost. QUESTION 3 1.02 moles 02 0.042 moles O2 0.4 moles O2 3.2 moles 02

Solution

1) from equation: 2 mol NaHCO3 = 1 mol Na2CO3

No of mol of NaHCO3 = w/M = 15.6/84 = 0.186 mol

No of mol of Na2CO3 remain = 0.186/2 = 0.093 mol

Amount of Na2CO3 remain = 0.093*106 = 9.86 g

answer: 9.8 g

2) from equation: 2 mol NaHCO3 = 1 mol CO2 = 1 mol H2O

No of mol of NaHCO3 = w/M = 15.6/84 = 0.186 mol

No of mol of CO2 remain = 0.186/2 = 0.093 mol

Amount of CO2 remain = 0.093*44 = 4.1 g

No of mol of H2O remain = 0.186/2 = 0.093 mol

Amount of H2O remain = 0.093*18 = 1.674 g

total mass lost= 4.1+1.674 = 5.774 g

answer: 5.8 g

3) mass of o2 lost = 4.832-3.474 = 1.358 g

   No of mol of O2 = 1.358/32 = 0.042

answer: 0.042 mol o2