Question

Chlorine is used by textile manufacturers to bleach cloth. Excess chlorine is destroyed by its reaction with sodium thiosulfate, Na2S2O3:

How many grams of Na2S2O3 are needed to react with 2.65 mol of H2O?


How many moles of HCl can form from 25.2 mol of Na2S2O3?


How many liters of Cl2 are required to produce 15.7 moles of NaHSO4?


How many molecules of HCl can form from 4.92 grams of H2O?

Answer 1

To find the number of grams of Na₂S₂O₃ needed to react with 2.65 mol of H₂O, multiply the number of moles by the molar mass of Na₂S₂O₃. To find the number of moles of HCl that can form, use the balanced equation and multiply the number of moles of Na₂S₂O₃ by the stoichiometric ratio. To find the number of liters of Cl₂ required, use the balanced equation and convert moles to liters using the ideal gas law equation. To find the number of molecules of HCl formed from a given mass of H₂O, use stoichiometry and Avogadro's number.

Step-by-step explanation:

1. To find the number of grams of Na₂S₂O₃ needed to react with 2.65 mol of H₂O, we need to use stoichiometry. The balanced equation shows a 1:1 ratio between H₂O and Na₂S₂O₃, so we know that 2.65 mol of Na₂S₂O₃ is needed. To find the mass, we can use the molar mass of Na₂S₂O₃ which is 158.11 g/mol. Multiplying the number of moles by the molar mass gives us the mass: 2.65 mol x 158.11 g/mol = 418.48 g.
2. To find the number of moles of HCl that can form from 25.2 mol of Na₂S₂O₃, we can use the balanced equation. From the equation, we see that there is a 1:2 ratio between Na₂S₂O₃ and HCl. So, the number of moles of HCl formed will be 2 times the number of moles of Na₂S₂O₃: 25.2 mol x 2 = 50.4 mol.
3. To find the number of liters of Cl₂ required to produce 15.7 moles of NaHSO₄, we can use the balanced equation. From the equation, we see that there is a 1:6 ratio between Cl₂ and NaHSO₄. So, the number of moles of Cl₂ required will be 1/6 times the number of moles of NaHSO₄: 15.7 mol / 6 = 2.62 mol. For the conversion of moles to liters, we need to use the ideal gas law equation: PV = nRT. Assuming constant temperature and pressure, we can rearrange the equation to solve for V (volume): V = nRT/P. Using the values for n (2.62 mol), R (0.0821 L·atm/mol·K), and P (1 atm), we can calculate V: V = 2.62 mol x 0.0821 L·atm/mol·K x 298 K / 1 atm = 64.1 L.
4. To find the number of molecules of HCl that can form from 4.92 grams of H₂O, we need to use stoichiometry. As we know, the molar mass of H₂O is 18.02 g/mol. First, we convert grams of H₂O to moles: 4.92 g H₂O x (1 mol / 18.02 g) = 0.273 mol H₂O. From the balanced equation, we know that there is a 1:2 ratio between H2O and HCl. So, the number of moles of HCl formed will be 2 times the number of moles of H₂O: 0.273 mol x 2 = 0.546 mol. Finally, to convert moles to molecules, we can use Avogadro's number (6.022 x 10²³ molecules/mol): 0.546 mol x (6.022 x 10²³ molecules/mol) = 3.29 x 10²³ molecules.