All categories

2 years ago

Please help!! i need the answer ASAP!

Chemistry

1 answer:

nirvana33 [79]2 years ago

7 0

Answer:

23.34 %.

Explanation:

The percentage of water must be calculated as a mass percent.

We need to find the mass of water, and the total mass in one mole of the compound. For that we need to use the atomic masses of each element and take in consideration the number of atoms of each element in the formula unit.

Atomic masses of the elements:

Cd: 112.411 g/mol, N: 14.0067 g/mol, O: 15.999 g/mol, and H: 1.008 g/mol.

Mass of the formula unit:

Cd(NO₃)₂•4H₂O

mass of the formula unit = (At. mass of Cd) + 2(At. mass of N) + 10(At. mass of O) + 8(At. mass of H) = (112.411 g/mol) + 2(14.0067 g/mol) + 10(15.999 g/mol) + 8(1.008 g/mol) = 308.5 g/mol.

Mass of water in the formula unit:

mass of water = (4 × 2 × 1.008 g/mol) + (4 × 15.999 g/mol) = 72.0 g/mol.

So, the percent of water in the compound = [mass of water / mass of the formula unit] × 100 = [(72.0 g/mol)/(308.5 g/mol)] × 100 = 23.34 %

You might be interested in

I need help with B and C

lakkis [162]

B) Mg is the alkaline earth metal w/12 protons so following the periodic table to the halogen in the same period is

Cl: Chlorine

C) The Neutral noble has w/ 18 electrons is argon so the metal in the same row is

Na: Sodium

8 0

3 years ago

The heat of fusion AH, of ethyl acetate (C4H802) is 10.5 kinol. Calculate the change in entropy as when 398. g of ethy, acetate

Hitman42 [59]

Answer: The entropy change of the ethyl acetate is 133. J/K

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass of ethyl acetate = 398 g

Molar mass of ethyl acetate = 88.11 g/mol

Putting values in above equation, we get:

$\text{Moles of ethyl acetate}=\frac{398g}{88.11g/mol}=4.52mol$

To calculate the entropy change for different phase at same temperature, we use the equation:

$\Delta S=n\times \frac{\Delta H_{fusion}}{T}$

where,

$\Delta S$ = Entropy change = ?

n = moles of ethyl acetate = 4.52 moles

$\Delta H_{fusion}$ = enthalpy of fusion = 10.5 kJ/mol = 10500 J/mol (Conversion factor: 1 kJ = 1000 J)

T = temperature of the system = $84.0^oC=[84+273]K=357K$

Putting values in above equation, we get:

$\Delta S=\frac{4.52mol\times 10500J/mol}{357K}\\\\\Delta S=132.9J/K$

Hence, the entropy change of the ethyl acetate is 133. J/K

7 0

2 years ago

What is the pH of 1.0M HI solution?

ozzi

Answer:

Explanation:

Since HI is a strong acid, the amoung of Hydrogen ions produced by it will be the same molar as the reactant. The negative log of the concentration will reveal that the pH is 0.

7 0

2 years ago

Read 2 more answers

How can you tell if an element has been oxidized or reduced in a reaction?

fomenos

Gaining of electrons is reduction and loss of electrons is oxidation.

Hope this helped! :)

7 0

3 years ago

Does this equation follow the Law of Conservation of Mass (Yes or No)

notka56 [123]

Yes I think it’s look right to me

3 0

2 years ago