Question

Задача 1 П’ятачок на день народження друга вирішив надути повітряні кульки. Допоможіть йому обчисліть об’єм Гелію, кількістю речовини 3,5 моль (н.у.). Задача 2 Вчителька за урок витрачає 15 г крейди. Обчисліть кількість речовини та кількість молекул CaCO3. Задача 3 Для приготування вечері Попелюшка використовує 1,5 моль NaCl. Обчисліть масу та кількість молекул солі. Задача 4 Водяний в своєму ставку має 3000·1023 молекул води. Обчисліть масу та об’єм води в ставку (н.у.). Задача 5 Фея квітів має 150·1023 молекул чарівного пилу, який має властивості газу. Обчисліть кількість речовини та об’єм чарівного пилу (н.у.).

Answer 1

1.) V＝n*Vm
V＝3.5*22.4＝78.4 л
2.)n＝m/M
n＝15/100＝0.15 моль
N＝n*Na
N＝0.15*6.02＝0.903*10(23 степени)
3) m＝n*M
m＝1.5*58.5＝87.75 г
N＝n*Na
N＝1.5*6.02＝9.03*10(23 степени)
4) n＝N/Na
n＝3000/6.02＝498.3*10(23 степени)
m＝n*M
m＝498.3*18＝8969.4 г
V＝n*Vm
V＝498.3*22.4＝11161.92 л
5) n＝N/Na
n＝150/6.02＝25*10(23 молекул)
V＝n*Vm
V＝25*22.4＝560 л

Answer 2

Problem 1: Calculating the Volume of Helium

To calculate the volume of helium, we need to use the ideal gas law equation, which states that PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature.

In this case, we are given the number of moles of helium (n = 3.5 mol) and we need to find the volume (V). However, we don't have information about the pressure or temperature. Without these values, we cannot calculate the volume accurately.

Please provide the values for pressure and temperature so that we can calculate the volume of helium.

Problem 2: Calculating the Amount of Substance and Number of Molecules of CaCO3

To calculate the amount of substance and the number of molecules of CaCO3, we need to use the molar mass of CaCO3 and the given mass of chalk.

The molar mass of CaCO3 is the sum of the atomic masses of calcium (Ca), carbon (C), and three oxygen (O) atoms. The atomic masses are as follows: - Calcium (Ca): 40.08 g/mol - Carbon (C): 12.01 g/mol - Oxygen (O): 16.00 g/mol

Therefore, the molar mass of CaCO3 is: 40.08 g/mol + 12.01 g/mol + (16.00 g/mol * 3) = 100.09 g/mol

Given that the teacher uses 15 g of chalk, we can calculate the amount of substance (n) using the formula: n = mass / molar mass

Substituting the values: n = 15 g / 100.09 g/mol ≈ 0.1499 mol

To calculate the number of molecules, we can use Avogadro's number, which is approximately 6.022 × 10^23 molecules/mol. Therefore, the number of molecules (N) is: N = n * Avogadro's number

Substituting the values: N = 0.1499 mol * 6.022 × 10^23 molecules/mol ≈ 9.01 × 10^22 molecules

So, the amount of substance of CaCO3 is approximately 0.1499 mol, and the number of molecules is approximately 9.01 × 10^22 molecules.

Problem 3: Calculating the Mass and Number of Molecules of NaCl

To calculate the mass and number of molecules of NaCl, we need to use the molar mass of NaCl and the given amount of substance.

The molar mass of NaCl is the sum of the atomic masses of sodium (Na) and chlorine (Cl). The atomic masses are as follows: - Sodium (Na): 22.99 g/mol - Chlorine (Cl): 35.45 g/mol

Therefore, the molar mass of NaCl is: 22.99 g/mol + 35.45 g/mol = 58.44 g/mol

Given that 1.5 mol of NaCl is used, we can calculate the mass (m) using the formula: m = amount of substance * molar mass

Substituting the values: m = 1.5 mol * 58.44 g/mol ≈ 87.66 g

To calculate the number of molecules, we can use Avogadro's number, which is approximately 6.022 × 10^23 molecules/mol. Therefore, the number of molecules (N) is: N = amount of substance * Avogadro's number

Substituting the values: N = 1.5 mol * 6.022 × 10^23 molecules/mol ≈ 9.033 × 10^23 molecules

So, the mass of NaCl is approximately 87.66 g, and the number of molecules is approximately 9.033 × 10^23 molecules.

Problem 4: Calculating the Mass and Volume of Water

To calculate the mass and volume of water, we need to use the given number of water molecules and Avogadro's number.

Given that there are 3000 × 10^23 molecules of water, we can calculate the mass using the molar mass of water, which is approximately 18.02 g/mol. The molar mass of water is the sum of the atomic masses of two hydrogen (H) atoms and one oxygen (O) atom. The atomic masses are as follows: - Hydrogen (H): 1.01 g/mol - Oxygen (O): 16.00 g/mol

Therefore, the molar mass of water is: 2 * 1.01 g/mol + 16.00 g/mol = 18.02 g/mol

To calculate the mass (m), we can use the formula: m = number of molecules * molar mass

Substituting the values: m = 3000 × 10^23 molecules * 18.02 g/mol ≈ 5.406 × 10^25 g

To calculate the volume (V) of water, we can use the formula: V = mass / density

The density of water is approximately 1 g/cm^3 or 1 g/mL.

Substituting the values: V = 5.406 × 10^25 g / 1 g/mL ≈ 5.406 × 10^25 mL

So, the mass of water is approximately 5.406 × 10^25 g, and the volume of water is approximately 5.406 × 10^25 mL.

Problem 5: Calculating the Amount of Substance and Volume of Magical Dust

To calculate the amount of substance and volume of magical dust, we need to use the given number of molecules and Avogadro's number.

Given that there are 150 × 10^23 molecules of magical dust, we can calculate the amount of substance (n) using Avogadro's number, which is approximately 6.022 × 10^23 molecules/mol. Therefore, the amount of substance is: n = number of molecules / Avogadro's number

Substituting the values: n = 150 × 10^23 molecules / 6.022 × 10^23 molecules/mol ≈ 2.49 mol

To calculate the volume (V) of magical dust, we need additional information such as the density or molar volume. Without this information, we cannot accurately calculate the volume.

Please provide the necessary information so that we can calculate the volume of magical dust.