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2 years ago

Calculate the molar solubility of lead thiocyanate in 1.00 M KSCN.

1 answer:

7 0

You have to make an assumption or estimation here: (don't think about the 1.00 M KSCN)
Since 1.00M KSCN provides a common ion source of SCN-. Therefore, you will have a 1.00 M SCN-.
[Pb+2][SCN-] ~ 0.01 x 0.02^2 = 4E-6
 Pb(SCN)2 <---> Pb++ + 2SCN- 

Bringing 1.00M SCN- back in the problem. 1.00M + 0.02M, ignoring the SCN-, and calculating the [Pb+2]:

Ksp = [Pb++][SCN-]^2
2.00E-5 = [Pb++](1.00)^2

[Pb++] = 2.00E-5 M 

The mass balance shows that: 

[Pb++] = [Pb(SCN)2] 

So [Pb(SCN)2] = 2.00E-5 M in 1.00 M KSCN.

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oth hydrogen sulfide (H2S) and ammonia (NH3) have strong, unpleasant odors. Which gas has the higher effusion rate? If you opene

Ksju [112]

Answer: Odor of ammonia would we detect first on the other side of the room.

Explanation:

To calculate the rate of diffusion of gas, we use Graham's Law.

This law states that the rate of effusion or diffusion of gas is inversely proportional to the square root of the molar mass of the gas. The equation given by this law follows:

$\text{Rate of diffusion}\propto \frac{1}{\sqrt{\text{Molar mass of the gas}}}$

$\frac{Rate_{H_2S}}{Rate_{NH_3}}=\sqrt{\frac{M_{NH_3}}{M_{H_2S}}}$

$\frac{Rate_{H_2S}}{Rate_{NH_3}}=\sqrt{\frac{17.031}{34.1}}$

$\frac{Rate_{H_2S}}{Rate_{NH_3}}=0.71$

Thus the odor of ammonia would we detect first on the other side of the room as the rate of effusion of ammonia would be faster as it has low molecular weight as compared to hydrogen sulphide.

5 0

3 years ago

Read 2 more answers

explain why the hydrogen atoms in a hydrogen gas molecule form nonpolar covalent bonds but oxygen and hydrogen atoms in water mo

marishachu [46]

Answer:

Explanation:

Covalent bond:

It is formed by the sharing of electron pair between bonded atoms.

The atom with larger electronegativity attract the electron pair more towards itself and becomes partial negative while the other atom becomes partial positive.

Non polar covalent bond:

It is the bond where both bonded atoms share the pair of electron equally.

For example:

Hydrogen gas (H₂) is non polar covalent compound because the electronegativity of both bonded atoms are same. No poles are created that's why this is non polar covalent compound.

Polar covalent bond:

It is the bond where both bonded atoms share the pair of electron unequally.

For example:

In water the electronegativity of oxygen is 3.44 and hydrogen is 2.2. That's why electron pair attracted more towards oxygen, thus oxygen becomes partial negative and hydrogen becomes partial positive and bond is polar.

7 0

3 years ago

You take three compounds consisting of two elements and decompose them. To determine the relative masses of X, Y, and Z, you col

miss Akunina [59]

Answer:

a) LAW OF MULTIPLE PROPORTIONS

b) 0.095g, 0.71g, 0.285g respectively

c) X2Y, YZ15, X6Y

d) hence mass of compound X = 21 x 0.045 = 0.95g

mass of compound Y = 21 x 0.955 = 20.05g

Explanation:

a) The assumptions made in solving this questions is the application of the LAW OF MULTIPLE PROPORTIONS. The Law of multiple proportions states that if two elements A and B combine together to form more than one compound, then the several masses of A which chemically combine with a fixed mass of B is in a simple ratio.

for example, copper forms two oxides ; copper(I) oxide (CuO) and copper(ii) oxide(Cu2O), it is possible for the two samples of the oxides to be reduced to Cu by reacting with Hydrogen gas. as such, certain masses of oxygen combine separately with a fixed mass of Cu. then the ratios of Cu are then determined.

b) To calculate the relative masses, we take note of the three compounds given, they all have some amount of Y in them, hence we can use Y as our relative mass, this implies that the relative mass of Y = 1g

mass of X = 0.4g

mass of Y = 4.2g

amount of X in 1g of Y = 0.4 x 1 /4.2

= 0.095g

for compound 2;

mass of Y = 1.4g

mass of Z = 1.0g

amount of Z in 1g of Y =1.0 x 1 /1.4

= 0.71g

for compound 3;

mass of X = 2.0g

mass of Y = 7.0g

amount of X in 1g of Y = 1 x 2/7

= 0.285g

c) Applying the law of multiple proportions; since elements X and Z combine with a fixed mass of Y, they must bear a simple ratio;

compound 1/compound 3 = 0.095/0.285

= 1/3

compound 1/compound 2 = 0.095/0.71

= 2/15

compound 2/ compound 3 = 0.71/0.285

= 5/2

formular for compound 1 = X2Y

formula for compound 2 = YZ15

formular for compound 3 = X6Y

d) from the formular X2Y, we can get the amount of each product in XY using the ratios

%of compound XY in X = mass of compound X / total Mass

= 0.2/4.4 = 4.5%

as such in a 21g of compound XY, %of compound Y = 1 - %of compound X = 95.5%

hence mass of compound X = 21 x 0.045 = 0.95g

mass of compound Y = 21 x 0.955 = 20.05g

5 0

2 years ago

which statement describes the way in which energy moves between a system of reacting substances and surroundings

V125BC [204]

The complete question is as follows: Which statement describes the way in which energy moves between a system reacting substances in the surroundings.

A) molecule Collisions transfer thermal energy between the system and its surroundings

B) The thermal energy of the system and it’s surroundings increase

C) The potential energy of the system and it’s surroundings increases

D) molecular collisions create energy that is then released into the surroundings

Answer: The statement, molecule Collisions transfer thermal energy between the system and its surroundings describes the way in which energy moves between a system reacting substances in the surroundings.

Explanation:

When there will occur an increase in kinetic energy of molecules then there will occur more number of collisions.

When kinetic energy between these molecules tends to decrease then they will release heat energy into their surroundings.

As a result, it means that molecule collisions transfer thermal energy between the system and its surroundings.

Thus, we can conclude that the statement molecule Collisions transfer thermal energy between the system and its surroundings describes the way in which energy moves between a system reacting substances in the surroundings.

8 0

2 years ago

What’s the answers to these?

nata0808 [166]

Answer:

0bervation

Explanation:

cause it is

5 0

3 years ago