Question

The number of oxygen atoms in 4.4 g of

CO2 is

(A) 6 × 10²³ (B) 11 × 10²³

(C) 12 × 10²³ (D) 1.2 × 10²³​

Answer 1

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$\implies$$\large\bf{\underline{\red{VERIFIED✔}}}$

$Moles\:of\:CO2\:=444.4\\=0.1 moles\\ ∴ Number\:of\:molecules\:of\:CO2\\=0.1×6.022×1 {0}^{23}\\=6.022×1 {0}^{22}\:molecules.\\But 1 molecule\:of \:CO2\:contains\:2\:oxygen\:atoms.\\∴ Number\:of\:oxygen \:atoms\: =2×6.022×1 {0}^{22} \\ =12.044×1 {0}^{22}\:atoms \\ =1.2×1 {0}^{23}  atoms$

So, Option D) 1.2 × 10²³ is Correct Answer.

$\boxed{I \:Hope\: it's \:Helpful}$

Answer 2

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(D) 1.2 ×10^23

QUESTION

The number of oxygen atoms in 4.4 g of CO2 is

OPTIONS

(A) 6 × 10²³

(B) 11 × 10²³

(C) 12 × 10²³

(D) 1.2 × 10²³

FORMULA USED

$number \: of \: molecules \: in \: given \: weight=\frac{given \: weight}{molecular \: mass} \times 1 \: mole$

$1 \: mole = 6.023 × {10}^{23} \: or \: 6 \times {10}^{23}$

WE KNOW

C stands for atomic symbol of Carbon

O stands for atomic symbol of oxygen

atomic mass of nitrogen (C) is 12

atomic mass of hydrogen (O) is 16

SOLUTION

step 1

calculate the molecular mass of CO2

CO2= C+O+O

= C +2O

molecular mass = atomic mass of carbon + 2 x atomic mass of oxygen

$= 12 + 2 \times 16 \\ 12 + 32 \\ 44$

so molecular mass of CO2 is 44 u

step 2

calculate the number of molecules in given weight

$\begin{gathered}\frac{given \: weight}{molecular \: mass} \times 1mole \\ = \frac{4.4}{44} \times 6 \times {10}^{23} \\ \frac{1}{10} \times 6 \times {10}^{23} \\ 6 \times {10}^{22} \end{gathered}$

step 3

calculate number of atoms

$number \: of \: atoms =no \: of \: molecules \: \times number \: of \: atoms \: of \: oxygen \: in \: one \: molecule \\ 6 \times {10}^{23} \times 2\\ 2 \times 6 \times {10}^{23} \\ 12 \times {10}^{23} \\ 1.2 \times {10}^{23}$

HOPE IT HELPS