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3 years ago

Asap please help !!!!

Chemistry

1 answer:

Liula [17]3 years ago

5 0

Answer: What do you need help with?

Explanation:

A biome is a collection of plants and animals that have common characteristics for the environment they exist in. They can be found over a range of continents. Biomes are distinct biological communities that have formed in response to a shared physical climate.

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An object's mass is less on<br> the Moon than it is on Earth.

vovikov84 [41]

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The mass of objects remains constant throughout the universe. This is because an object is made of he same amount of matter (atoms), no matter where you take it in the universe. If you take an object from the Earth to the moon, only the weight will change.

Explanation:

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3 years ago

WRITING AND BALANCING EQUATIONS

Natasha2012 [34]

Answer:

CaCO3 + 2HCl —> CaCl2 + CO2 + H2O

Explanation:

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4 years ago

When there is an imbalance in a body system, and the body cannot maintain homeostasis, how might other systems respond?

Ulleksa [173]

Other systems in the body might respond with cramps or overheating, which might eventually kill you, if not taken care of in time. Hope this helps!

8 0

4 years ago

a) Whatis the composition in mole fractions of a solution of benzene and toluene that has a vapor pressure of 35 torr at 20 °C?

iogann1982 [59]

Answer:

molar composition for liquid

xb= 0.24

xt=0.76

molar composition for vapor

yb=0.51

yt=0.49

Explanation:

For an ideal solution we can use the Raoult law.

Raoult law: in an ideal liquid solution, the vapor pressure for every component in the solution (partial pressure) is equal to the vapor pressure of every pure component multiple by its molar fraction.

For toluene and benzene would be:

$P_{B}=x_{B}*P_{B}^{o}$

$P_{T}=x_{T}*P_{T}^{o}$

Where:

$P_{B}$ is partial pressure for benzene in the liquid

$x_{B}$ is benzene molar fraction in the liquid

$P_{B}^{o}$ vapor pressure for pure benzene.

The total pressure in the solution is:

$P= P_{T}+ P_{B}$

And

$1=x_{B}+x_{T}$

Working on the equation for total pressure we have:

$P=x_{B}*P_{B}^{o} + x_{T}*P_{T}^{o}$

Since $x_{T}=1-x_{B}$

$P=x_{B}*P_{B}^{o} + (1-x_{B})*P_{T}^{o}$

We know P and both vapor pressures so we can clear $x_{B}$ from the equation.

$x_{B}=\frac{P- P_{T}^{o}}{ P_{B}^{o} - P_{T}^{o}}$

$x_{B}=\frac{35- 22}{75-22} = 0.24$

$x_{T}=1-0.24 = 0.76$

To get the mole fraction for the vapor we know that in the equilibrium:

$P_{B}=y_{B}*P$

$y_{T}=1-y_{B}$

$y_{B} =\frac{P_{B}}{P}=\frac{ x_{B}*P_{B}^{o}}{P}$

$y_{B}=\frac{0.24*75}{35}=0.51$

$y_{T}=1-0.51=0.49$

Something that we can see in these compositions is that the liquid is richer in the less volatile compound (toluene) and the vapor in the more volatile compound (benzene). If we take away this vapor from the solution, the solution is going to reach a new state of equilibrium, where more vapor will be produced. This vapor will have a higher molar fraction of the more volatile compound. If we do this a lot of times, we can get a vapor that is almost pure in the more volatile compound. This is principle used in the fractional distillation.

7 0

3 years ago

How much calcium can be recovered from 75.0g of calcium fluoride

7nadin3 [17]

38.46g

Explanation:

Given parameters:

Mass of CaF₂ = 75.0g

Unknown:

Mass of calcium that can be recovered = ?

Solution:

This is a mass percentage problem and we need to solve it accordingly.

To solve this problem;

Find the molar mass of CaF₂

Find the ratio between the molar mass of Ca and that of CaF₂

Multiply by the given mass

Molar mass of CaF₂ = 40 + (2 x 19) = 78g/mol

Mass of calcium = $\frac{40}{78}$ x 75 = 38.46g

learn more:

Mass percentage brainly.com/question/8170905

#learnwithBrainly

3 0

3 years ago