A. The four isotopes of lead are shown below, each with its percent by mass abundance, the composition of its nucleus

At constant pressure and 25^0C , a sample of gas occupies 4.5lit. at what temperature will the gas occupy 9.0lit.

olga55 [171]

Answer:

Final temperature = 149 K

Explanation:

Given data:

Initial temperature = 25°C (25+273 = 298 K)

Initial volume = 4.5 L

Final temperature = ?

Final volume = 9.0 L

Solution:

The given problem will be solve through the Charles Law.

According to this law, The volume of given amount of a gas is directly proportional to its temperature at constant number of moles and pressure.

Mathematical expression:

V₁/T₁ = V₂/T₂

V₁ = Initial volume

T₁ = Initial temperature

V₂ = Final volume

T₂ = Final temperature

Now we will put the values in formula.

V₁/T₁ = V₂/T₂

T₂ = T₁V₂/V₁

T₂ = 4.5 L × 298 K / 9.0 L

T₂ = 1341 L K / 9.0L

T₂ = 149 K

4 0

2 years ago

Three identical flasks contain three different gases at standard temperature and pressure. Flask A contains CH4, flask B contain

erastovalidia [21]

Answer:

FLASK B WHICH CONTAINS CO2 HAS THE HIGHEST NUMBER OF MOLECULES AS IT CONTAINS THE HIGHEST MOLECULAR MASS OF 44 G/MOL.

Explanation:

Flask A contains CH4

Flask B contaims CO2

Flask C contains N2

To know the flask containing the largest number of molecules, we find the molar mass of the molecules in the flask and the largest is the one with the highest number of the relative molecular mass.

Molecular Mass of CH4 (C = 12, H =1) = ( 12 + 1*4) g/mol

= 16 g/mol

Molecular mass of CO2 (C= 12, 0= 16) = (12 + 16*2) g/mol

= 12 + 32 g/mol

= 44 g/mol

Molecular mass of N2 (N=14) = 14 * 2 g/mol

= 28 g/mol

Hence, the flask with the largest number of molecules is the flask with the highest relative molecular mass. The highest molecular mass is 44 g/mol and it is for the gas CO2 in Flask B.

So therefore, Flask B has the highest number of molecules in it.

4 0

2 years ago

Consider this equilibrium:

zheka24 [161]

It is C). <span>It decreases as the concentration of products increases.</span>

3 0

2 years ago

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If 500.0 ml of 0.10 m ca2+ is mixed with 500.0 ml of 0.10 m so42−, what mass of calcium sulfate will precipitate? ksp for caso4

attashe74 [19]

Answer : The mass of calcium sulfate precipitate will be, 6.12 grams

Solution :

First we have to calculate the moles of $Ca^{2+}$ and $SO_4^{2-}$ .

$\text{Moles of }Ca^{2+}=\text{Molarity of }Ca^{2+}\times \text{Volume of }Ca^{2+}=0.10mole/L\times 0.5L=0.05\text{ moles}$

$\text{Moles of }SO_4^{2-}=\text{Molarity of }SO_4^{2-}\times \text{Volume of }SO_4^{2-}=0.10mole/L\times 0.5L=0.05\text{ moles}$

As, 0.05 moles of $Ca^{2+}$ is mixed with 0.05 moles of $SO_4^{2-}$ , it gives 0.05 moles of calcium sulfate.

Now we have to calculate the solubility of calcium sulfate.

The balanced equilibrium reaction will be,

$CaSO_4\rightleftharpoons Ca^{2+}+SO_4^{2-}$

The expression for solubility constant for this reaction will be,

$K_{sp}=(s)\times (s)$

$K_{sp}=(s)^2$

Now put the value of $K_{sp}$ in this expression, we get the solubility of calcium sulfate.

$2.40\times 10^{-5}=(s)^2$

$s=4.89\times 10^{-3}M$

Now we have to calculate the moles of dissolved calcium sulfate in one liter solution.

$\text{Moles of }CaSO_4=\text{Molarity of }CaSO_4\times \text{Volume of }CaSO_4=4.89\times 10^{-3}mole/L\times 1L=4.89\times 10^{-3}\text{ moles}$

Now we have to calculate the moles of calcium sulfate that precipitated.

$\text{Moles of }CaSO_4\text{ precipitated}=\text{Moles of }CaSO_4\text{ present}-\text{Moles of }CaSO_4\text{ dissolved}$

$\text{Moles of }CaSO_4\text{ precipitated}=0.05-4.89\times 10^{-3}=0.045\text{ moles}$

Now we have to calculate the mass of calcium sulfate that precipitated.

$\text{Mass of }CaSO_4\text{ precipitated}=\text{Moles of }CaSO_4\text{ precipitated}\times \text{Molar mass of }CaSO_4$

$\text{Mass of }CaSO_4\text{ precipitated}=0.045moles\times 136g/mole=6.12g$

Therefore, the mass of calcium sulfate precipitate will be, 6.12 grams

5 0

2 years ago

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What is the relationship of rocks to minerals.

Dovator [93]

Rocks are made up of minerals

8 0

3 years ago

Read 2 more answers