Question

Hey anybody pls answer this question plss​

Answer 1

Answer:

Q1) for this we have to find out the number of moles in each sample.

note that 1 mole of any compound or sample will have same number of molecules.

i) 68g of NH3

first of all, molar mass of NH3 = 14+3 = 17g

so, 17g of NH3 is 1 mole.

then, 1g of NH3 is 1/17 mole

and then 68g of NH3 is 1/17 × 68 = 4 mole.

so, 4 moles of NH3 weighs 68g.

ii)28 g of N2

1 mole of N2 --> 14×2 = 28g.

iii) 49g of H2SO4

1 mole of H2SO4 --> 2+32+(16×4) = 34+64 = 98g.

therefore, 1g of h2so4 is 1/98 mole

and, 49g is 1/98 × 49 = 0.5 moles of H2SO5

iv)128 g of O2

1 mole of O2 --> 16×2 = 32g

1g of O2 --------> 1/32 mole

128g of O2 ----> 1/32 × 128 = 4 moles.

As you can see, 68g NH3 and 128g O2 have same number of moles. therefore, they will have same number of molecules.

Q2) 49g of H2SO4 have 0.5 moles of H2SO4.

therefore, this sample will have the least number of molecules.

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hope it helps you

Answer 2

Answer:

no.of moles = given mass/molar mass

with this you can easily solve this question.

refer to the first answer for the whole solution