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3 years ago

Which change of state is shown in the model?

Chemistry

1 answer:

Shalnov [3]3 years ago

3 0

Answer:

Deposition

Explanation:

The process of deposition is when an object goes from a gas to a solid. In the picture, the first container had a gas (molecules were far apart). In the second, the molecules were tightly packed (a solid).

Hope this helps!

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The amount of work done depends on the amount of force applied and the distance the distance the object moves.

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What is the square root of 10 Can you guys subscribe to my friend pls, it would mean a lot

Korolek [52]

Answer:

3.16228

Explanation:

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3 years ago

A cord is used to vertically lower an initially stationary block of mass m kg at a constant downward acceleration of g/4. the bl

Natali5045456 [20]

(a) We know that work is the product of Force and Distance so: (in this case Distance is negative since going down so –d)

work = force * distance

work = M * (g - g/4) * -d

work = -3Mgd/4 

(b) The work by the weight of the block is simply:

work = Mgd 

(c) The kinetic energy is simply equivalent to the net work, therefore:

KE = net work

KE = Mgd/4 

(d) The velocity is:

v = √(2*KE/M)

Plugging in the value of KE from c:

v = √(2*Mgd / 4M)

v = √(gd / 2)

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3 years ago

An aqueous KNO3 solution is made using 72.5 g of KNO3 diluted to a total solution volume of 2.00 L. Calculate the molarity, mola

Sonja [21]

Answer:

The molarity is 0.359 $\frac{moles}{L}$

The molality is 0.354 $\frac{moles}{kg}$

The mass percent of the solution es 3.45%

Explanation:

Molarity is a unit of concentration that indicates the amount of moles of solute that appear dissolved in each liter of the mixture. It is determined by:

$Molarity (M)=\frac{number of moles of solute}{volume}$

Being:

K: 39 g/mole
N: 14 g/mole
O: 16 g/mole

The molar mass of KNO₃ is:

KNO₃= 39 g/mole + 14 g/mole + 3*16 g/mole= 101 g/mole

You can apply the following rule of three: if 101 grams of KNO₃ are present in 1 mole, 72.5 grams in how many moles are present?

$moles of KNO_{3}=\frac{72.5 grams*1 mole}{101 grams}$

moles of KNO₃= 0.718

So you have:

moles of KNO₃= 0.718
volume= 2 L

Applying this quantity in the definition of molarity:

$molarity=\frac{0.718 moles}{2 L}$

Molarity= 0.359 $\frac{moles}{L}$

The molarity is 0.359 $\frac{moles}{L}$

Molality is a way of measuring the concentration of solute in solvent and indicates the amount of moles of solute in each kilogram of solvent.

Then the molality is calculated by:

$Molality=\frac{moles of solute}{mass of solvent in kilograms}$

Density is defined as the property that matter, whether solid, liquid or gas, has to compress in a given space. That is, it is the amount of mass per unit volume. So, if the density of 1.05 g / mL for the solution indicates that in 1 mL of solution there are 1.05 grams of solution, in 2000 mL (where 2L = 2000 mL, because 1 L = 1000mL) how much mass is there?

$mass=\frac{2000 mL*1.05 grams}{1 mL}$

mass= 2100 grams

Since mass solution = mass water + mass KNO₃

then mass water = mass solution - mass KNO₃

Being mass solution 2100 grams and mass KNO₃ 72.5 grams, and replacing you get: mass water= 2100 grams - 72.5 grams

mass water= 2,027.5 grams

Then, being:

moles of KNO₃= 0.718
mass of solvent in kilograms= 2.0275 kg (being 2,027.5 grams= 2.0275 kilograms because 1,000 grams= 1 kilogram)

Replacing in the definition of molality:

$molality=\frac{0.718 moles}{2.0275 kg}$

molality= 0.354 $\frac{moles}{kg}$

The molality is 0.354 $\frac{moles}{kg}$

The mass percent of a solution is the number of grams of solute per 100 grams of solution. Then the mass percent is the mass of the element or solute divided by the mass of the compound or solute and the result of which is multiplied by 100 to give a percentage.

$mass percent=\frac{mass of solute}{mass of solution} *100$

So, in this case:

$mass percent=\frac{72.5 grams}{2100 grams} *100$

mass percent= 3.45 % KNO₃ by mass

The mass percent of the solution es 3.45%

3 0

3 years ago

A 232 mL cup of whole milk contains about 27 mg of cholesterol. Express the cholesterol concentration of the milk in kilograms p

son4ous [18]

Explanation:

Cholesterol concentration = 27 mg/ 232 mL

Change unit mg/ml to kg/m³

1 kg = 1000 g

1 g = 1000 mg

1 kg = 1000000 mg

1 kg = 10⁶ mg

10⁶ mg = 1 kg

1 mg = 10^-6 kg

m³ = 1000 L

1 L = 1000 mL

m³ = 1000000 mL

m³ = 10⁶ mL

10⁶ mL = m³

1 mL = 10^-6 m³

Cholesterol concentration = 27 mg/ 232 mL

27 × 10^-6 kg/ 232 × 10^-6 m³

= 27/232 kg/m³

6 0

3 years ago