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3 years ago

What is the molality of a solution made by dissolving 5.2 g of NaCl in 100 g of water?

Chemistry

1 answer:

stich3 [128]3 years ago

8 0

Answer:

The molality is 0,89

Explanation:

A molal solution indicates the moles of solute in 1 kg of solvent (1000 g). First, we calculate the weight of 1 mol of NaCl:

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

58,5 g----1 mol NaCl

5,2 g----x=(5,2 gx1 mol NaCl)/58,5 g=0,089 mol NaCl

100g water-----0,089 mol NaCl

1000g water----x=(1000g waterx0,089 mol NaCl)/100 g water

x=0,89 mol NaCl----> 0,89 m

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PLEASE HELP ME WITH A COUPLE OF QUESTIONS!!! Thank You :)

Brrunno [24]

Hey there!

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5 0

3 years ago

At a festival, spherical balloons with a radius of 280. Cm are to be inflated with hot air and released. The air at the festival

evablogger [386]

Answer:

8608.18 balloons

Explanation:

Hello! Let's solve this!

Data needed:

Enthalpy of propane formation: 103.85kJ / mol

Specific heat capacity of air: 1.009J · g ° C

Density of air at 100 ° C: 0.946kg / m3

Density of propane at 100 ° C: 1.440kg / m3

First we will calculate the propane heat (C3H8)

3000g * (1mol / 44g) * (103.85kJ / mol) * (1000J / 1kJ) = 7.08068 * 10 ^ 6 J

Then we can calculate the mass of the air with the heat formula

Q = mc delta T

m = Q / c delta T = (7.08068 * 10 ^ 6 J) / (1.009J / kg ° C * (100-25) ° C) =

m = 93566.96kg

We now calculate the volume of a balloon.

V = 4/3 * pi * r ^ 3 = 4/3 * 3.14 * 1.4m ^ 3 = 11.49m ^ 3

Now we calculate the mass of the balloon

mg = 0.946kg / m3 * 11.49m ^ 3 = 10.87kg

The amount of balloons is

93566.96kg / 10.87kg = 8608.18 balloons

5 0

3 years ago

Read 2 more answers

High-pressure liquid chromatography (HPLC) is a method used in chemistry and biochemistry to purify chemical substances. The pre

kotykmax [81]

Answer:

3.41 x10⁶ torr

Explanation:

To solve this problem we need to remember the equivalency:

1 torr = 133.322 Pa

Then we can proceed to convert 4.55×10⁸ Pa into torr. To do that we just need to multiply that value by a fraction number, putting the unit that we want to convert from in the denominator, and the value we want to convert to in the numerator:

4.55x10⁸ Pa * $\frac{1torr}{133.322Pa} =$ 3.41 x10⁶ torr

6 0

3 years ago

Effect of fossil fuel emission on oceans?

BlackZzzverrR [31]

Fossil fuel emissions can create acid rain, which in turn increases the pH of ocean water, harming the organisms in the ocean.

7 0

4 years ago

A 2.912 g sample of a compounds containing only C, H, and O was completely oxidized in a reaction that yielded 3.123 g of water

Taya2010 [7]

Answer:

Explanation:

18 gram of water contains 2 g of hydrogen

3.123 gram of water will contain 2 x 3.123 / 18 = .347 g of hydrogen .

44 gram of carbon dioxide contains 12 g of carbon

7.691 gram of carbon dioxide will contain 12 x 7.691 / 44 = 2.1 g of carbon .

So the sample will contain 2.912 - ( .347 + 2.1 ) g of oxygen .

= .465 g of oxygen .

moles of Carbon = 2.1 / 12 = .175

moles of hydrogen = .347 / 1 = .347

moles of oxygen = .465 / 16 = .029

Ratio of moles of carbon , oxygen and hydrogen ( C,O,H )

= 0.175 : 0.029 : 0.347

= .175/ .029 : 1 : .347 / .029

= 6 : 1 : 12

So empirical formula = C₆H₁₂O

Let the molecular formula be $(C_6H_{12}O)_n$

molecular weight = n ( 6 x 12 + 12x 1 + 16)

= 100 n

Given 100 n = 100.1

n = 1

Molecular formula = C₆H₁₂O.

3 0

3 years ago