Mastering Moles: How to Calculate Mass in Chemistry

3.42 moles of CaO are equivalent to how many grams of CaO?

• A. 64 g CaO
• B. 80 g CaO
• C. 192 g CaO
• D. 150 g CaO

Answer: (C)

To determine the mass of calcium oxide (CaO) in grams when given a specific number of moles, you can use the molar mass of CaO. The molar mass is calculated by adding the atomic weights of calcium (Ca) and oxygen (O). Calcium has an atomic mass of approximately 40.08 g/mol, and oxygen has an atomic mass of about 16.00 g/mol. Therefore, the molar mass of CaO is: \[ 40.08 \, \text{g/mol (Ca)} + 16.00 \, \text{g/mol (O)} = 56.08 \, \text{g/mol (CaO)} \] Next, to find out how many grams correspond to 3.42 moles of CaO, you multiply the number of moles by the molar mass: \[ 3.42 \, \text{moles} \times 56.08 \, \text{g/mol} = 192.00 \, \text{g} \] This calculation shows that 3.42 moles of CaO is equivalent to 192 grams. Hence, the choice that indicates 192 g of CaO

As you prepare for the Algonquin College Health Program Assessment (AC-HPAT), diving into the world of chemistry can feel a bit like learning a new language. But don't sweat it! We're going to break down the process of converting moles to grams in a way that’s relatable and easy to remember. So, let’s tackle a common problem: How do you find the grams equivalent to a certain number of moles?

What's the Deal with Moles?

You know what? Moles are a chemist's best friend. It's a unit that helps us count particles—like atoms and molecules—just as a dozen helps us count eggs. A mole equals about (6.022 \times 10^{23}) particles. But in everyday terms, it helps us tie together the microscopic world of particles with our macroscopic world of things we can actually see!

Now, let’s talk specifics—like calcium oxide, or CaO. You might be wondering, “What does this all have to do with calcium oxide, and how do I calculate its mass from moles?” Great question! Knowing the molar mass of CaO is key.

Molar Mass: The Key to Unlocking Grams

To find out how many grams of CaO correspond to a certain number of moles, you start with the molar mass. This is basically the weight of one mole of a substance. For calcium oxide, here’s how you calculate it:

1. Start with calcium (Ca), which has an atomic mass of approximately 40.08 g/mol.

2. Then, add the atomic mass of oxygen (O), which is about 16.00 g/mol.

So the molar mass of CaO can be summed up like this:

[

40.08 , \text{g/mol (Ca)} + 16.00 , \text{g/mol (O)} = 56.08 , \text{g/mol (CaO)}

]

Got that? Now we’ve got the molar mass, and we’re ready for the next step!

Doing the Math: Converting Moles to Grams

Let's say we have 3.42 moles of CaO. How do we find out how many grams that is? It's quite straightforward! Just multiply the number of moles by the molar mass:

[

3.42 , \text{moles} \times 56.08 , \text{g/mol} = 192.00 , \text{grams}

]

And there you have it! Three point four two moles of CaO equals 192 grams. Pretty neat, huh? This calculation demonstrates the straightforward nature of using molar mass to get a grasp on quantities in chemistry.

Why Is This Important?

You might be asking yourself why understanding these conversions matters. Well, in fields like healthcare, having a solid foundation in chemistry is not just a “nice to have.” It’s essential! Knowing how different substances react, their properties, and how to measure them accurately can impact everything from diagnostics to treatment.

Wrapping It Up

As you study for your AC-HPAT, keep practicing these kinds of problems. Think about moles like tokens in a game—everyone needs to understand how many tokens they’ve got to win. The more comfortable you become with calculations like the conversion of moles to grams, the easier it will be to tackle more complex problems down the road.

So, the next time someone throws a mole problem your way, remember the handy little formula, focus on that molar mass, and you’ll be ready to shine. Happy studying!