Question

Q.15] Long Answers
1 - Write the names of the following compounds and deduce their molecular masses.
Na2SO4, K2CO3, CO2, MgCl2 NaOH, AIPO4, NaHCO3.
(Knowledge/Application)​

Answer 1

Answer:

hii kaise ho and kkhrh ho

Answer 2

Answer:

i. Na2SO4 : Sodium Sulphate

Steps for finding the molecular mass:

Molecular mass of Na2SO4 = 2(Atomic mass of Na) + 1(Atomic mass of S) + 4(Atomic mass of O)

⇒ Molecular Mass = 2(23) + 1(32) + 4(16)

= 46 + 32 + 64

= 142 g/mol

ii.K2CO3: Potassium Carbonate

Steps for finding the molecular mass:

Molecular mass of K2CO3 = 2× (Atomic mass of K) + 1× (Atomic mass of C) + 3× (Atomic mass of O)

Molecular Mass = 2× (39) + 1× (12) + 3× (16)

= 78 + 12 + 48

= 138 g/mol

iii.CO2:- Carbondioxide

Molecular mass of CO2 = 1× (Atomic mass of C) + 2× (Atomic mass of O)

Molecular Mass = 1× (12) + 2× (16)

= 12 + 32

= 44 g/mol

iv.NaOH:Sodium Hydroxide

Molecular mass of NaOH = 1× (Atomic mass of Na) + 1× (Atomic mass of O) + 1× (Atomic mass of H)

Molecular Mass = 1× (23) + 1× (16) + 1× (1)

= 23 + 16 + 1

= 40 g/mol

v.MgCl2:Magnesium Chloride

Molecular mass of MgCl2 = 1× (Atomic mass of Mg) + 2× (Atomic mass of Cl)

Molecular Mass = 1× (24) + 2× (35.5)

= 24 + 70

= 94 g/mol

vi.AlPO4:-Aluminium Phosphate

Molecular mass of AlPO4 = 1× (Atomic mass of Al) + 1× (Atomic mass of P) + 4× (Atomic mass of O)

Molecular Mass = 1× (27) + 1× (31) + 4× (16)

= 27 + 31 + 64

= 122 g/mol

vii.NaHCO3: Sodium Bicarbonate

Molecular mass of NaHCO3 = 1× (Atomic mass of Na) + 1× (Atomic mass of H) + 1× (Atomic mass of C) + 3× (Atomic mass of O)

Molecular Mass = 1× (23) + 1× (1) + 1× (12) + 3× (16)

= 23 + 1 + 12 + 48

= 84 g/mol