Question

If 0.2 mol of the following substances are required how many grams of those substances should be taken
sodium chloride, magnesium oxide , calcium carbonate​

Answer 1

Answer:

Explanation: we the formula no. Moles = given weight/ molecular weight

Therefore Nacl requires is 11.7 grams

Mgo=4gmrs

Caco3=10 grms

Answer 2

1) Sodium Chloride:

Given: Number of moles of sodium chloride (NaCl)= 0.2 mol

To find: Mass in grams of 0.2 mol of NaCl

Solñ: Molecular mass of NaCl

= (Atomic mass of Na)× 1+ (Atomic mass of Cl)× 1

= 23× 1+ 35.5× 1

= 23+ 35.5

Molecular mass of NaCl= 58.5

According to the formula,

Number of moles in the given NaCl (n)

= Mass of NaCl in grams/ Molecular mass of NaCl

0.2= Mass of NaCl in grams/ 58.5

Mass of NaCl in grams= 0.3× 58.5

Mass of NaCl in grams= 11.7 g

Mass of 0.2 mole of NaCl is 11.7 g

2) Magnesium oxide:

Given: Number of moles of Magnesium oxide (MgO)= 0.3 mol

To find: Mass in grams of 0.2 mol of MgO

Solñ: Molecular mass of MgO

= (Atomic mass of Mg)× 1+ (Atomic mass of O)× 1

= 24× 1+ 16× 1

= 24+ 16

Molecular mass of MgO= 40

According to the formula

Number of moles in the given MgO (n)

= Mass of MgO in grams/ Molecular mass of MgO

0.2 = Mass of MgO in grams/ 40

Mass of MgO in grams= 0.2× 40

Mass of MgO in grams= 8 g.

Mass of 0.2 mole pf MgO is 8 g

3) Calcium Carbonate

Given: Number of moles of Calcium Carbonate (CaCO3)= 0.2 mol

To find: Mass in grams of 0.2 mol of CaCO3

Solñ: Molecular mass of CaCO3

= (Atomic mass of CA)× 1+ (Atomic mass of C)× 1+ (Atomic mass of O)× 3

= (40× 1)+ (12× 1)+ (16× 3)= 40+ 12+ 48

Molecular mass of CaCO3= 100

According to the formula

Number of moles in the given CaCO3 (n)

= Mass of CaCO3 in grams/ Molecular mass of CaCO3

0.2= Mass of CaCO3 in grams/ 100

Mass of CaCO3 in grams= 0.2× 100

Mass of CaCO3 in grams= 20 g

Mass of 0.2 mole of CaCO3 is 20 g