Question

tell all the answers for all the questions

Answer 1

Hey mate!! Here are your answers.
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(1)

Atomic mass of NH3

= (14)+(1×3)
= 14 + 3
= 17 u

Now, atomic mass is equal to Gram Molecular Mass(GMM)

Hence, GMM of NH3 = 17g

Now, 1 mole of any compound is equal to its Gram Molecular Mass

Therefore,
17 g = 1 mole of NH3

1 g = 1/17 mole of NH3

Hence,
34 g
= 1/17 × 34 mole of NH3
= 2 moles of NH3

Hence, 34 g of NH3 has 2 moles
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(2) (a)

Atomic mass of O2 = 8 × 2
= 16 u

Now, atomic mass = GMM

Hence, GMM of O2 = 16g

Now, we know that, GMM of any compound = Avogadro's number (6.022 × 10^23 molecules)

Hence,
16 g of O2 = 6.022 × 10^23 molecules
1 g of O2 = 6.022 × 10^23/16

Hence,
8 g of O2
= 6.022 × 10^23 ×8/16
= 6.022 × 10^23/2
= 3.022 × 10^23 molecules

Therefore, 8g of O2 has 3.022 × 10^23 molecules
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(2) (b)

Atomic mass of He = 4 u

Since, atomic mass = GMM,
So, GMM of He = 4 g

GMM = 1 mole

Then,
4 g of He = 1 mole
1 g of He = 1/4 mole

Hence,
52 g of He
= 1×52/4
= 52/4
= 13 moles.

Hence, 52 g of He is equal to 13 moles.
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(3) (a)

Atomic mass of O2 = 8×2
= 16 u

Atomic mass = GMM
So, GMM of O2 = 16 g

Now,
16 g of O2 = 1 mole
1 g of O2 = 1/16 moles

Hence,
64 g of O2
= 1×64/16
= 64/16
= 4

Therefore, 64 g of Oxygen atom is equal to 4 moles
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(3) (b)

1 mole of any compound = Avogadro's number

So,
6.022 × 10^23 atoms = 1 mole
1 atom = 1/6.022×10^23 moles

Hence,
24.088 × 10^23 atoms
= 1 × 24.088 ×10^23/6.022×10^23
= 24.088×10^23/6.022×10^23
= 4 moles.

Therefore, 24.088×10^23 atoms of Oxygen atom = 4 moles.
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(4)

(i) HCl - diatomic

(ii) H2 - diatomic

(iii) H2O - Polyatomic

(iv) NH3 - Polyatomic
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(5)

(i) Magnesium Hydroxide - Mg(OH)2

(ii) Hydrogen sulphide - H2S

(iii) Potassium Chloride - KCl

(iv) Calcium Oxide - CaO

(v) Barium Chloride - BaCl2

(vi) Sodium carbonate - Na2Co3
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Hope the answer helps you.