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4 years ago

SOMEONE HELP ME PLEASEEEE 99 POINTS!!!!!!!!

Chemistry

2 answers:

Monica [59]4 years ago

8 0

I'm not completely understanding what you're asking here.

Lostsunrise [7]4 years ago

3 0

The most popular concept maps are in web form meaning they start with one singular statement or idea and branch out, connecting terms and visually showing the relationships between certain aspects. So for example you could use waves as your basic idea and branch out to the kinds of waves and then adding the terms in your concept bank in where they belong. Be sure to be as specific as possible and make it easy to read/understand (make sure everything is visible)

You might be interested in

How many Al atoms are present in 2.5 moles of Al2O3

inysia [295]

Answer:

1.5*10^24

Explanation:

1 mol of any substance contains 6.02*10^23 particles of this substance.

2.5*6.02*10^23 =1.5*10^24

8 0

4 years ago

A jet airplane has a velocity of 1145 knots. A knot is 1 nautical mile (nm)/hr. A nautical

ra1l [238]

Answer:

589.038 m/s

Explanation:

i dont know if did this right tho

4 0

2 years ago

How many moles are in 15.2 grams of Calcium (Ca)?

nalin [4]

Answer:

There are 0.379 moles of Ca in the given sample.

Explanation:

Hey there!

We're given that we have 15.2 grams of Ca (Calcium). We need to convert grams to moles.

There are many different conversion types for moles. A few examples are:

grams to moles
moles to grams
grams to particles
moles to liters

There are really endless possibilities for conversion factors. Since we want to find the number of moles in a certain sample, we first need to define what a mole is.

Mole - a unit of measurement in chemistry

A mole is one unit of a certain item. For instance, one cup would be equivalent to one mole. Moles are simply a hypothetical unit in chemistry that act as a placeholder.

Now, how do we find the number of moles?

We know that a mole of something is one of that substance. In this case, we're referring to one atom of Calcium.

Therefore, we need to reference a periodic table to understand what the mass of one atom of calcium is equivalent to. I'll be using the official AP Chemistry periodic table as issued by the College Board.

When we reference the periodic table, we see the mass of one atom of calcium is equivalent to 40.08 amu (atomic mass units).

We learn in chemistry that we can use the terms amu and grams interchangeably, so we have learned that one mole of calcium is equivalent to 40.08 grams.

How do we work this out?

Now, we need to find out how many moles are in 15.2 grams of calcium. We can use dimensional analysis to work this out.

Our starting unit will be 15.2 grams of Ca.

$\text{15.2 grams Ca}$

We want to convert this into moles, so we need to cancel out our grams value. Additionally, since we know that we have 40.08 grams of Ca in one mole, we can set these up as two ratios:

$\displaystyle \frac{\text{40.08 grams Ca}}{\text{1 mole Ca}}$
$\displaystyle \frac{\text{1 mole Ca}}{\text{40.08 grams Ca}}$

These ratios can be used to express the relationship between the moles of calcium and the mass of one calcium atom. However, we need our value of grams to cancel out, so since we will be using cross multiplication in our dimensional analysis, we need to use the ratio with grams on the bottom.

Now that we have selected our ratio, we can set up a multiplication problem of our two ratios:

$\displaystyle \text{15.2 grams Ca} \times \frac{\text{1 mole Ca}}{\text{40.08 grams Ca}}$

We assume that we have a denominator of 1 below 15.2 grams Ca.

Now, we perform our multiplication.

$\displaystyle \frac{\text{15.2 grams Ca} \ \times \ \text{1 mole Ca}}{\text{40.08 grams Ca}}$

We see that our remaining unit is going to be mole(s) Ca, so we can go ahead and drop our grams Ca unit.

$\displaystyle \frac{\text{15.2} \ \times \ \text{1 mole Ca}}{\text{40.08}}$

Now, we need to simplify a little bit.

$\displaystyle \frac{\text{15.2}}{\text{40.08}} = \text{? moles Ca}$

Finally, let's divide our fraction and evaluate our equation to find the value of moles Ca.

$\displaystyle \frac{15.2}{40.08} = \text{0.379241517 moles Ca}$

Are we done yet?

Not just yet! To complete our work, we need to find the number of significant figures we can use. We are given two values in which we can use to judge how many significant figures we are limited to.

15.2 -- Three significant figures
40.08 -- Four significant figures

In chemistry, we always use the least number of significant figures for precision calculations, so we need to round our answer to three significant figures.

$0.379241517 \approx 0.379$

Therefore, there are approximately 0.379 moles of Ca in the given sample.

7 0

3 years ago

Drag the labels onto the table to indicate when each statement Is true. Labels can be used once, more than once, or not at all.

liq [111]

The labels the table to indicate when each statement Is true. Labels can be used once, more than once, or not at all, The orange dye moves independently of the purple dye. 2. Concentration gradients exist that drive diffusion of both dyes. : free water, solute, free water, solute.

In chemistry, attention is the abundance of a constituent divided by way of the total quantity of an aggregate. several types of mathematical descriptions may be prominent: mass concentration, molar concentration, range concentration, and quantity concentration.

it's miles the amount of solute dissolves in one hundred g solvent. If the attention of the answer is 20 %, we understand that there are 20 g solutes in one hundred g solution. instance: 10 g salt and 70 g water are mixed and the solution is ready. find awareness of the answer by means of percentage mass.

Learn more about concentration here:

brainly.com/question/26255204

#SPJ4

3 0

1 year ago

Substances that absorb energy in the form of heat are

Yanka [14]

Answer:

Substances that absorb energy in the form of heat are

b)endothermic.

hope it helps :)

7 0

3 years ago

Read 2 more answers