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2 years ago

I need help with this someone help

Chemistry

1 answer:

allochka39001 [22]2 years ago

6 0

Answer:

1. Element is Ca

2. 20 electrons

3. 2 valence electrons

4. 4 energy levels

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What is the concentration, in m/v percent, of a solution prepared from 50 g NaCl and 2.5 L of solution?

Serjik [45]

When we convert the given mass in grams and volume in liters to m/v percent, we recall that m/v percent is expressed as grams/100 milliliters. In this case the expression becomes (50 grams/ 2500 L)*(0.1L/100ml), that is equal to 0.002 grams/ 100 mL. Hence the the concentration is equal to 0.2 m/v percent.

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3 years ago

How many moles are in 213 grams of NaCl?

Nata [24]

Answer:

There are 3, 64 moles of NaCl.

Explanation:

First we calculate the mass of 1 mol of NaCl, starting from the atomic weights of Na and Cl obtained from the periodic table. Then we calculate themoles in 213 grams of NaCl, making a simple rule of three:

Weight NaCl= Weight Na + Weight Cl = 23 g + 35, 5 g= 58, 5 g/ mol

58,5 g ------1 mol NaCl

213 g---------x= (213 g x 1 mol NaCl)/ 58, 5 g= 3, 64 mol NaCl

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4 years ago

What are the three kind of rocks that are apart of the rock cycle???

pav-90 [236]

Why, Hello There! The 3 Kinds of rocks that are apart of the rock cycle is...

1.Sedimentary

2.Metamorphic

And

3.Igneous

Hoped i helped!

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3 years ago

Read 2 more answers

What is the molarity of a solution in which 250 grams of NaCl are dissolved in 2.9 L of water?

Maksim231197 [3]

Answer:

About 1.48 M.

Explanation:

The formula for molarity is mol/L.

So firstly, you must find the amount of moles in 250 grams of NaCl.

I do this by using stoichiometry. First, I find how nany grams are in a single mole of NaCl. This is around 58.44 grams/mole. Now that I know this, I can now use a stoich table. (250 g NaCl * 1 mol NaCl / 58.44 g NaCl). I plug this into my calculator.

I get that 250 grams of NaCl is equal to about 4.28 moles.

Now I just plug into the formula!

4.28 moles/2.9 L = about 1.48

I've attached a picture of my personal notes below which shows work I have done in similar equations.

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2 years ago

How do air masses flow?

zepelin [54]

How do air masses flow?

from regions of high pressure to low pressure

In general, cold air masses tend to flow toward the equator and warm air masses tend to flow toward the poles.

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3 years ago