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2 years ago

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Strontium crystallizes in a face-centered cubic unit cell having an edge length of 77.43 pm. What is the atomic radius of stront

ium (in picometers) based on this structure

1 answer:

kiruha [24]2 years ago

5 0

Answer:

Atomic radius of Strontium is 27.38pm

Explanation:

In a face-centered cubic structure, the edge, a, could be obtained using pythagoras theorem knowing the hypotenuse of the unit cell, b, is equal to 4r:

a² + a² = b² = (4r)²

2a² = 16r²

a = √8 r

As edge length of Strontium is 77.43pm:

77.43pm / √8 = r

27.38pm = r

<h3>Atomic radius of Strontium is 27.38pm</h3>

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What is the molarity of a solution in which 58g of nacl are dissolved in 1.0 l of solution

Lady_Fox [76]

Hey there :

Molar mass of NaCl = 58.44 g/mol

Number of moles :

n = mass of solute / molar mass

n = 58 / 58.44

n = 0.9924 moles of NaCl

Volume = 1.0 L

Therefore:

Molarity = number of moles / volume ( L )

Molarity = 0.9924 / 1.0

Molarity = 0.9924 M

Hope that helps!

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2 years ago

when a chemical change occurs, what do you know about the amount of matter in the new substances? what is this known as?( is it

Pavel [41]

Explanation:

The law of conservation of mass states that the total mass of the products is equal to the total of the reactants.

A chemical change occurs because of a chemical reaction.

In a chemical reaction, the reactants are the starting substances and the products is the finishing substances. The amount of each type of atoms to start with and end with are also equal.

No matter disappears after a chemical reaction.

Answer:

The amount of matter in the new substances is the same as the original.

This is known as the law of conservation of mass.

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2 years ago

Phosphorus trichloride gas and chlorine gas react to form phosphorus pentachloride gas: PCl3(g)+Cl2(g)⇌PCl5(g). A 7.5-L gas vess

Tpy6a [65]

Answer:

The equilibrium constant in terms of concentration that is, $K_c=3.6243\times 10^{3}$ .

Explanation:

$PCl_3(g)+Cl_2(g)\rightleftharpoons PCl_5(g)$

The relation of $K_c\& K_p$ is given by:

$K_p=K_c(RT)^{\Delta n_g}$

$K_p$ = Equilibrium constant in terms of partial pressure.=98.1

$K_c$ = Equilibrium constant in terms of concentration =?

T = temperature at which the equilibrium reaction is taking place.

R = universal gas constant

$\Delta n_g$ = Difference between gaseous moles on product side and reactant side= $n_{g,p}-n_{g.r}=1-2=-1$

$98.1=K_c(RT)^{-1}$

$98.1 =\frac{K_c}{RT}$

$K_c=98.1\times 0.0821 L atm/mol K\times 450 K=3,624.30=3.6243\times 10^{3}$

The equilibrium constant in terms of concentration that is, $K_c=3.6243\times 10^{3}$ .

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2 years ago

Read 2 more answers

43 milliliters of water weighs 43 g. what is the density of the water?

Anastaziya [24]

Answer:

$\rho =1g/mL$

Explanation:

Hello,

In this case, since the density is defined as the ratio between the mass and the volume as shown below:

$\rho =\frac{m}{V}$

We can compute the density of water for the given 43 g that occupy the volume of 43 mL:

$\rho =\frac{43g}{43mL}=1g/mL$

Regards.

4 0

2 years ago

Positive Deviation from Raoult's Law occurs when the vapour pressure of component is greater than what is expected in Raoult's L

8090 [49]

Answer:

All of the above.

Explanation:

In positive deviation from Raoult's Law occur when the vapour pressure of components is greater than what is expected value in Raoult's law.

When a solution is non ideal then it shows positive or negative deviation.

Let two solutions A and B to form non- ideal solutions.let the vapour pressure of component A is $P_A$ and vapour pressure of component B is $P_B$ .

$P^0_A$ = Vapour pressure of component A in pure form

$P^0_B$ = Vapour pressure of component B in pure form

$x_A$ =Mole fraction of component A

$x_B=$ =Mole fraction of component B

The interaction between A- B is less than the interaction A- A and B-B interaction.Therefore, the escaping tendency of liquid molecules in mixture is greater than the escaping tendency in pure form.Hence, the vapour pressure of a mixture is greater than the initial value of vapour pressure.

$P_A >P^0_A\cdot x_A$ , $P_B>P^0_B\cdot x_B$

Therefore, $P_A+P_B >P^0_A\cdot x_A+P^0_B \cdot x_B$

Therefore, the enthalpy of mixing is greater than zero and change in volume is greater than zero.

Hence, option a,b,c and d are true.

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2 years ago