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| 1. |
Calculate the number of Cl- and Ca2+ ions in 222g anhydrous CaCl2 |
| Answer» The chemical formula and molar mass of calcium chloride are respectively CaCl2 and 111 g respectively. Thus, there are 6.022{tex}\\times{/tex}1023 formula units in 111g of CaCl2. So,number of formula units of CaCl2 in 111 g of CaCl2 = 6.022 {tex}\\times{/tex}1023number of formula units of CaCl2 in 1g of CaCl2 = {tex}\\frac{(6.022\\times1023)}{111}{/tex}number of formula units in 222g of CaCl2 ={tex}\\frac{(6.022\\times1023\\times222)}{111}{/tex}\xa0= 12.044 {tex}\\times{/tex} 1023Now, each formula unit of CaCl2 contains one Ca2+ ion and two Cl- ions. Thereforenumber of Ca2+ ions in one unit of CaCl2 = 1number of Ca2+ ions in 12.044 {tex}\\times{/tex} 1023 units of CaCl2 = 1 {tex}\\times{/tex} 12.044 {tex}\\times{/tex} 1022 = 1.2044 {tex}\\times{/tex} 1024Similarlynumber of Cl- ions in one unit of CaCl2 = 2number of Cl- ions in 12.044 {tex}\\times{/tex} 1023 units of CaCl2 = 2 {tex}\\times{/tex} 12.044 {tex}\\times{/tex} 1023= 2.4088 {tex}\\times{/tex} 1024Hence, there are 1.2044 {tex}\\times{/tex} 1024 Ca2+ ions and 2.4088 {tex}\\times{/tex} 1024 Cl- ions in 222 g of CaCl2. | |