How would you prepare 250 mL of 0.150 M solution of CaCl2 from a 3.00 M stock solution? Specify the glassware that should be used.

Video transcript

Hey everyone, we're asked to describe the preparation of 450 mL of a 0.250 molar solution of hydroxide ions. If a stock solution of 3.50 moller calcium hydroxide is available in the laboratory, include the appropriate glassware to be used. Now before we look at our answer choices, let's go ahead and try and figure this out on our own first. We want to determine the polarity of our hydroxide ions and we can do so by starting off with our 3.50 moller of our calcium hydroxide, which is going to be 3.50 mol of our calcium hydroxide. Over leaders, we can look at our multiple ratios and as we can see right here, one mole of calcium hydroxide contains two mol of our hydroxide ions. So when we calculate this out and cancel out our units, we end up with um polarity of 7.0 molar of hydroxide ions. Now that we have the polarity of our hydroxide ions, we can use the formula M one V one equals M two V two, plugging in our values for our first polarity, we have 7.50 moller And this is going to be multiplied by RV one and this will be equal to 450 ml Times 0.250 Molar which was provided to us in the question stem calculating for our volume one, we're going to divide both sides by 7.50 moller this will get us to a volume Of 16.1 ml which is going to be our final answer. Now looking at our answer choices, it looks like answer choice B matches what we calculated and that's going to be in a 100 millimeter graduated cylinder, measures 16.1 mL of the 30.50 moller calcium hydroxide. Transfer the 16.1 millimeter into a 500 millimeter volumetric flask, then fill to mark with distilled water. And the reason why we chose B instead of C is because we want that volumetric flask instead of the beaker. Now I hope that made sense and let us know if you have any questions.