Question

Identify the substance which has same number of molecules in 14g N2
a) 3.4g NH3
b) 15g NO
c)64g O2
d) 32g SO2
e)1g H2
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Answer 1

We need to know the number of molecules which is number of moles * Avogadro’s number
So
We need to compare number of moles because Avogadro’s numbers is constant for all
We’ll start with Nitrogen gas : 14g/28g.mol=0.5 mole

For NH3 : 3.4g / (14+3)g.mol= 0.2 mol
For NO. : 15g/(14+16)g.mol = 0.5 mol
For O2 : 64g/32 g.mol = 2 mol
For SO2: 32g /( 32+32) g.mol = 0.5mol
For H2. : 1g/ 2g.mol = 0.5 mol

So
H2& SO2 & NO have the same number of moles of N2 and the same number of molecules of N2