Question

3. How many grams are there in1.806. 1022 molecules of MgCl2 ппллииззззззззззззззз​

Answer 1

N=NA*n;

n=N/NA= 1.806*10^22/6.02*10^23=0.03

n=m/M;

m(MgCl2)=95*0.03=2.85(g)

Ответ: 2.85g

Answer 2

To calculate the number of grams in a given number of molecules of a substance, you need to use the concept of molar mass. Molar mass is the mass of one mole of a substance and is usually expressed in grams per mole (g/mol).

The molar mass of magnesium chloride (MgCl2) can be calculated by adding the atomic masses of magnesium (Mg) and chlorine (Cl) together.

• Atomic mass of Mg: ~24.31 g/mol
• Atomic mass of Cl: ~35.45 g/mol (since chlorine exists as Cl2 in MgCl2)

Molar mass of MgCl2 = 24.31 g/mol (Mg) + 2 * 35.45 g/mol (2 * Cl) = 95.21 g/mol

Now, you can use Avogadro's number (6.022 x 10^23) to convert the given number of molecules (1.806 x 10^22) to moles:

Number of moles = Number of molecules / Avogadro's number Number of moles = 1.806 x 10^22 / 6.022 x 10^23 ≈ 0.03 moles

Finally, you can calculate the mass using the molar mass:

Mass (grams) = Number of moles * Molar mass Mass (grams) = 0.03 moles * 95.21 g/mol ≈ 2.8563 grams

So, there are approximately 2.8563 grams in 1.806 x 10^22 molecules of MgCl2.