Question

calculate no. of atom in 53g of co2

Answer 1

Here is your answer...☺️

$given \: mass \: = 53g \\ \\ mola r \: mass \: of \: CO_{2} \\ = 12 + 2 \times 16 \\ = 12 + 32 = 44 \: g \: {mol}^{ - 1} \\ \\ no \: of \: moles \: ,n \: = \frac{given \: mass \: }{molar \: mass} \\ \\ = \frac{53g}{44 \: g \: {mol}^{ - 1} } \\ \\ = 1.204 \: mol \\ \\ no. \: of \:a toms \: present \: = n \times N_{A} \\ \\ = 1.204 \times 6.022 \times {10}^{23} \\ \\ = 7 .25 \times {10}^{23} atoms$

Answer 2

Hey!
 First you need to know the percentage composition of C and O in CO2.
 The %comp. of C will be- 12/44 *100=27.27%
The % comp. of O will be - 16*2/44 *100=72.72%
So mass of C in 53g -27.27% * 53=14.45g
AND, mass of O-72.72% *53=38.54g