Question

How many moles of o2 are there in 1.20x10^22 oxygen molecules?

Answer 1

$\huge\bf{\red{Solution:-}}$

$\boxed{\sf{1\:mole\:of\:O_2= 6.022\times 10{}^{23} molecule}}$

$\sf\underline{\blue{A.T.Q:-}}$

$\sf\implies 1\:mole\:of\:O_2= 6.022\times 10{}^{23} molecule\\ \\ \sf\implies x\:mole= 1.20\times 10{}^{22} molecule\\ \\ \sf\:\: {\purple{Now\: Cross\: multiplication}}\\ \\ \sf\implies 1.20\times 10{}^{22}= 6.022\times 10{}^{23}\times x\\ \\ \sf\implies x=\dfrac{1.20\times 10{}^{22}}{6.022\times 10{}^{23}}\\ \\ \sf\implies x=\cancel{\dfrac{1.20\times 10{}^{22}}{6.022\times 10{}^{23}}}\\ \\ \sf\implies x=0.0199mole$

$\boxed{\sf{\purple{0.0199moles\:in\:1.20\times 10{}^{22} molecule\:of\:O_2}}}$

Answer 2

we know that,

$\red{ 1 mole=6.022×10 {}^{23} }$

so,$\red {1.20×10 {}^{22} \: atom \: of \: o2 = \frac{1}{6.022 \times 10 {}^{23} } \times 1.20 \times 10 {}^{22} }$

$\red{ =>0.019 \: moles}$

Thus, 1.20×10²² atoms of oxygen are 0.019 moles...