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Calculate the mass of Ca(OH)₂ in a sample if the calcium hydroxide is neutralized by

22.50mL of 0.500M HCI according to the following equation:

2HCI (aq) + Ca(OH)₂ (s)→ 2H₂O (i) + CaCl₂ (aq)

User Bastiat
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Final answer:

To calculate the mass of Ca(OH)2 in the sample, we need to determine the number of moles of HCl used in the titration. From the balanced chemical equation, we can see that 2 moles of HCl react with 1 mole of Ca(OH)2. Finally, the mass of Ca(OH)2 in the sample is 0.417 g.

Step-by-step explanation:

To calculate the mass of Ca(OH)2 in the sample, we need to determine the number of moles of HCl used in the titration. From the balanced chemical equation, we can see that 2 moles of HCl react with 1 mole of Ca(OH)2. So, if 22.50 mL of 0.500 M HCl is used, we can calculate the number of moles of HCl:

Moles of HCl = ​(volume of HCl in L) x (concentration of HCl in M)

Moles of HCl = (22.50 mL) x (0.500 M / 1000 mL/L) = 0.01125 mol HCl

Since 2 moles of HCl react with 1 mole of Ca(OH)2, we can establish the mole ratio as follows:

Mole ratio of Ca(OH)2 to HCl = 1 mole Ca(OH)2 / 2 moles HCl

Therefore, the number of moles of Ca(OH)2 can be calculated:

Moles of Ca(OH)2 = (0.01125 mol HCl) x (1 mole Ca(OH)2 / 2 moles HCl) = 0.00563 mol Ca(OH)2

Finally, we can calculate the mass of Ca(OH)2:

Mass of Ca(OH)2 = (moles of Ca(OH)2) x (molar mass of Ca(OH)2)

The molar mass of Ca(OH)2 can be calculated as follows:

Molar mass of Ca(OH)2 = (molar mass of Ca) + 2 * (molar mass of O) + 2 * (molar mass of H)

Using the atomic masses from the periodic table, we find:

Molar mass of Ca(OH)2 = (40.08 g/mol) + 2 * (16.00 g/mol) + 2 * (1.01 g/mol) = 74.10 g/mol

Therefore, the mass of Ca(OH)2 in the sample is:

Mass of Ca(OH)2 = (0.00563 mol Ca(OH)2) x (74.10 g/mol)

= 0.417 g

User Tomab
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