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a 0.400 g sample of ca(oh)2 (molar mass 74.1 g/mol) reacts completely with 25.0 ml of hcl solution. what is the molarity of the hcl? answer in units of molarity to 3 significant figures. g

User Erbridge
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Answer:

To determine the molarity of the HCl solution, we need to use the given information and apply the concept of stoichiometry.

First, let's calculate the number of moles of Ca(OH)2 using its molar mass:

Number of moles of Ca(OH)2 = Mass / Molar mass

Number of moles of Ca(OH)2 = 0.400 g / 74.1 g/mol

Number of moles of Ca(OH)2 = 0.0054 mol

Next, we need to find the stoichiometric ratio between Ca(OH)2 and HCl from the balanced chemical equation. Assuming a balanced equation is provided, let's say it is:

Ca(OH)2 + 2HCl → CaCl2 + 2H2O

From the balanced equation, we can see that 1 mole of Ca(OH)2 reacts with 2 moles of HCl.

Therefore, the number of moles of HCl required to react completely with the given amount of Ca(OH)2 is:

Number of moles of HCl = 2 * Number of moles of Ca(OH)2

Number of moles of HCl = 2 * 0.0054 mol

Number of moles of HCl = 0.0108 mol

Now, let's calculate the molarity of the HCl solution:

Molarity = Number of moles of solute / Volume of solution in liters

Given that the volume of the HCl solution is 25.0 ml, we need to convert it to liters:

Volume of solution = 25.0 ml = 25.0/1000 = 0.025 L

Now we can calculate the molarity of the HCl solution:

Molarity = 0.0108 mol / 0.025 L

Molarity = 0.432 M (rounded to 3 significant figures)

Therefore, the molarity of the HCl solution is 0.432 M.

Step-by-step explanation:

User Rene Pickhardt
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