Question

Обчисліть маси безводноï соді і води у наступних кристалогідратах: а) мідного купоросу масою 62,5 г; б) глауберової солі масою 80,5 г; в) залiзного купоросу масою 278 г; г) манган (II) сульфат гептагiдрату MnSO4 +7H2O масою 138,5 г; д) ферум(III) хлориду нонагідрату FeCl3.9H2O масою 64,9 г .​

Answer 1

Я на фото трохи накреслила, надіюсь все зрозуміло
д) дано:
m(FeCl3*9H2O)=64,9 г
Знайти: m(FeCl3); m(H2O)
Розв’язання:
у 324,5 г FeCl3*9H2O є 162,5 г FeCl3
у 64,9 г FeCl3*9H2O є х г FeCl3
x=162,5*64,9/324,5= 32,5 г FeCl3
m(H2O)=64,9-32,5=32,4 г

Answer 2

Calculation of Masses of Anhydrous Salt and Water in Crystal Hydrates

To calculate the masses of anhydrous salt and water in crystal hydrates, we need to consider the molar masses of the compounds involved and use stoichiometry.

Let's calculate the masses for each of the given crystal hydrates:

a) Copper(II) sulfate pentahydrate (CuSO4 · 5H2O) with a mass of 62.5 g:

To calculate the mass of the anhydrous salt (CuSO4), we need to subtract the mass of water (H2O) from the total mass of the compound.

The molar mass of CuSO4 is 159.61 g/mol, and the molar mass of H2O is 18.02 g/mol.

First, let's calculate the number of moles of CuSO4 · 5H2O: Number of moles = mass / molar mass Number of moles = 62.5 g / (159.61 g/mol + 5 * 18.02 g/mol)

Now, let's calculate the mass of CuSO4: Mass of CuSO4 = Number of moles * molar mass of CuSO4

b) Sodium sulfate decahydrate (Na2SO4 · 10H2O) with a mass of 80.5 g:

To calculate the mass of the anhydrous salt (Na2SO4), we need to subtract the mass of water (H2O) from the total mass of the compound.

The molar mass of Na2SO4 is 142.04 g/mol, and the molar mass of H2O is 18.02 g/mol.

First, let's calculate the number of moles of Na2SO4 · 10H2O: Number of moles = mass / molar mass Number of moles = 80.5 g / (142.04 g/mol + 10 * 18.02 g/mol)

Now, let's calculate the mass of Na2SO4: Mass of Na2SO4 = Number of moles * molar mass of Na2SO4

c) Iron(III) sulfate heptahydrate (Fe2(SO4)3 · 7H2O) with a mass of 278 g:

To calculate the mass of the anhydrous salt (Fe2(SO4)3), we need to subtract the mass of water (H2O) from the total mass of the compound.

The molar mass of Fe2(SO4)3 is 399.88 g/mol, and the molar mass of H2O is 18.02 g/mol.

First, let's calculate the number of moles of Fe2(SO4)3 · 7H2O: Number of moles = mass / molar mass Number of moles = 278 g / (399.88 g/mol + 7 * 18.02 g/mol)

Now, let's calculate the mass of Fe2(SO4)3: Mass of Fe2(SO4)3 = Number of moles * molar mass of Fe2(SO4)3

d) Manganese(II) sulfate heptahydrate (MnSO4 · 7H2O) with a mass of 138.5 g:

To calculate the mass of the anhydrous salt (MnSO4), we need to subtract the mass of water (H2O) from the total mass of the compound.

The molar mass of MnSO4 is 151.00 g/mol, and the molar mass of H2O is 18.02 g/mol.

First, let's calculate the number of moles of MnSO4 · 7H2O: Number of moles = mass / molar mass Number of moles = 138.5 g / (151.00 g/mol + 7 * 18.02 g/mol)

Now, let's calculate the mass of MnSO4: Mass of MnSO4 = Number of moles * molar mass of MnSO4

e) Iron(III) chloride nonahydrate (FeCl3 · 9H2O) with a mass of 64.9 g:

To calculate the mass of the anhydrous salt (FeCl3), we need to subtract the mass of water (H2O) from the total mass of the compound.

The molar mass of FeCl3 is 162.20 g/mol, and the molar mass of H2O is 18.02 g/mol.

First, let's calculate the number of moles of FeCl3 · 9H2O: Number of moles = mass / molar mass Number of moles = 64.9 g / (162.20 g/mol + 9 * 18.02 g/mol)

Now, let's calculate the mass of FeCl3: Mass of FeCl3 = Number of moles * molar mass of FeCl3

Please note that the calculations above are based on the assumption that the given masses are accurate and the compounds are pure.

Let me know if you need any further assistance!