Question

254 CHAPTER 7 Chemical Quantities and Reactions 7.81 A dandruff shampoo contains dipyrithione. C N.OS which acts as an antibacterial and antifungal agent. (7.1.72.7.3) a. What is the molar mass of dipyrithione? b. How many moles of dipyrithione are in 25.0 g? c. How many moles of Care in 250 g of dipyrithione? d. How many moles of dipyrithione contain 8.2 X 10- atoms b. wr c. in PO of N? 7.86 If pe repo head& shoulders pyrithione zinc dandruff shampet Dandruff shampoo shampooing antipelliculaire au pyrithioned contains dipyrithione. 7.82 Ibuprofen, an anti-inflammatory drug in Advil, has the formula C13H1802. (7.1, 7.2, 7.3) 7.8 for

Answer 1

7.810) . a). Molecular mass of dipyrithione (C10H8N2O2S2) = 12x10 + 8 + 14x2 + 16x2 + 32x2 = 252 g/mol

b). mole in 25 g of it = 25 / 252 = 0.0992 mol

c). 1 mol of dipyrithione have 10 mole of C atom

then , 0.0992 mol of dipyrithione have 10 x 0.0992 mole = 0.992 mol of carbon

d). mole of N in 8.2 x 10^24 = 8.2x10^24 / (6.022x10^23) = 13.616 mole

2 mol of nitrogen is present in 1 mole of dipyrithione (c10h8n2o2s2 )

1mol of nitrogen is present in 1/2 mole of dipyrithione

so, 13.616 mol of nitrogen is present in 13.616 / 2 mole of dipyrithione = 6.808 moles .

7.93. a). grams in 0.15 mole of k = 0.15 x mol wt. of K

= 0.15 x 39 = 5.85 g

b) . grams of Cl2 = 0.15 x 70.9 = 10.635 g

c). grams of Na2CO3 = 0.15 x 286 = 42.9 g