Mastering Dilutions: What You Need to Know for the ALAT Exam

When preparing a 1:3 dilution of substance B using 10 ml, what is the final volume of the solution?

• A. 20 ml
• B. 30 ml
• C. 40 ml
• D. 50 ml

Answer: (C)

To prepare a 1:3 dilution using a total of 10 ml of solution, you need to consider the dilution ratio, which indicates that for every one part of the substance being diluted (substance B), there are three parts of the diluent, resulting in a total of four parts. In this case, the total volume consists of 1 part substance B and 3 parts diluent. When you combine these, you set up the following relationship: - 1 part of substance B (1 part) + 3 parts of diluent = 4 parts total. Given that you are using 10 ml for the entire solution: - Each part would then represent 10 ml / 4 parts = 2.5 ml. Thus, for the final solution: - You will use 1 part substance B which is 2.5 ml, - And then you will have 3 parts of diluent which totals 7.5 ml (3 parts x 2.5 ml). Adding these together gives you: - 2.5 ml (substance B) + 7.5 ml (diluent) = 10 ml. However, since the question focuses on making a 1:3 dilution

When preparing for the Assistant Laboratory Animal Technician (ALAT) exam, mastering the basics can make a big difference—especially in dilution calculations! Take, for instance, the common 1:3 dilution. It might sound straightforward, but let’s break it down in a way that’s not just informative but truly engaging.

You know what? Understanding dilutions can be a bit like baking. When you’re whipping up a recipe, you need to adjust your ingredients based on the number of servings. For instance, if you wanted to make a batch of frosting and the recipe called for a certain amount, but you only had a small cake, you wouldn’t want to make too much—you’d have to scale it right back. Just like that, when preparing a 1:3 dilution, you need to know how to scale the substance and the diluent correctly.

So, if we dive into our specific problem: “When preparing a 1:3 dilution of substance B using 10 ml, what is the final volume of the solution?” At first glance, you might think the answer is 30 ml, right? Not quite!

Let’s sift through the math. The 1:3 dilution tells us something crucial. For every 1 part of our substance, we’re adding 3 parts of diluent. In total, that’s 4 parts—the substance and the diluent together. So, if you start with 10 ml of substance B (which represents those 1 part), here’s the magic formula:

Final Volume = Volume of substance × Total parts

Final Volume = 10 ml × 4

Final Volume = 40 ml

Ta-da! The final volume of your 1:3 dilution is indeed 40 ml! This clarity in understanding ratio and proportion will serve you well not only for the ALAT exam but in practical applications within the lab.

But here’s the thing—we often overlook these little details in the rush of study prep. Ask yourself: how often do you need to apply these skills in your future role? Whether you're adjusting doses of medication or preparing specimens, having this knowledge in your toolkit is invaluable.

Need more practice? Try calculating dilutions with different starting volumes or ratios! It’s a fun exercise that not only solidifies your learning but also boosts your confidence as you prepare. Remember, mastering these foundational skills keeps you ahead in a career that’s as rewarding as it is challenging.

So why not take a moment? Go grab a piece of paper and challenge yourself with a few dilution problems today. You’ll thank yourself later when you’re breezing through the ALAT exam!