Question

ПОМОГИТЕ РЕШИТЬ ЗАДАЧИ НЕ ПОНИМАЮ РЕШИТЕ ПЖАЛУЙСТАРасчитайте массу и число молекулсоединений, взятых количеством вещества:а) 2,2 моль Mg(OH)2б)12 моль Li2O ЛЮДИ ПОМОГИТЕ

Answer 1

 

m=n*M

N=n*Nа              Nа= 6*10^23 молекул\моль - постоянная

 

М(Mg(OH)2)= 24+(16+1)*2= 58г/моль

m=2.2 моль*58г/моль=127,6г

N(Mg(OH)2)=2.2моль*6*10^23 молекул/моль=13.2*10^23молекул

 

 

М(Li2O)=7*2+16=30 г\моль

m = 12 моль*30г/моль=360 г

N=12моль*6*10^23 молекул/моль=72*10^23 молекул

Answer 2

Calculation of Mass and Number of Molecules in Compounds

To calculate the mass and number of molecules in a compound, we need to know the molar mass of the compound and the amount of substance (in moles) of the compound.

The molar mass of a compound is the mass of one mole of that compound and is calculated by summing the atomic masses of all the atoms in the compound. The amount of substance (in moles) is given.

Let's calculate the mass and number of molecules for the given compounds:

a) 2.2 moles of Mg(OH)2: To calculate the mass, we need to know the molar mass of Mg(OH)2. Let's calculate it:

- The atomic mass of Mg is 24.31 g/mol. - The atomic mass of O is 16.00 g/mol. - The atomic mass of H is 1.01 g/mol.

The molar mass of Mg(OH)2 can be calculated as follows: (1 * atomic mass of Mg) + (2 * atomic mass of O) + (2 * atomic mass of H)

Now, let's calculate the molar mass of Mg(OH)2: (1 * 24.31 g/mol) + (2 * 16.00 g/mol) + (2 * 1.01 g/mol) = 58.33 g/mol

To calculate the mass, we can use the formula: mass = amount of substance * molar mass

Substituting the values: mass = 2.2 moles * 58.33 g/mol = 128.32 g

Therefore, the mass of 2.2 moles of Mg(OH)2 is 128.32 grams.

To calculate the number of molecules, we can use Avogadro's number, which is approximately 6.022 x 10^23 molecules/mol.

The number of molecules can be calculated as follows: number of molecules = amount of substance * Avogadro's number

Substituting the values: number of molecules = 2.2 moles * (6.022 x 10^23 molecules/mol) = 1.33 x 10^24 molecules

Therefore, the number of molecules in 2.2 moles of Mg(OH)2 is 1.33 x 10^24 molecules.

b) 12 moles of Li2O: Similarly, let's calculate the mass and number of molecules for 12 moles of Li2O.

The molar mass of Li2O can be calculated as follows: (2 * atomic mass of Li) + (1 * atomic mass of O)

- The atomic mass of Li is 6.94 g/mol. - The atomic mass of O is 16.00 g/mol.

Now, let's calculate the molar mass of Li2O: (2 * 6.94 g/mol) + (1 * 16.00 g/mol) = 29.88 g/mol

To calculate the mass: mass = amount of substance * molar mass mass = 12 moles * 29.88 g/mol = 358.56 g

Therefore, the mass of 12 moles of Li2O is 358.56 grams.

To calculate the number of molecules: number of molecules = amount of substance * Avogadro's number number of molecules = 12 moles * (6.022 x 10^23 molecules/mol) = 7.23 x 10^24 molecules

Therefore, the number of molecules in 12 moles of Li2O is 7.23 x 10^24 molecules.

I hope this helps! Let me know if you have any further questions.