Question

How many atoms in each element?
1. \[
  5C{H_3}C{O_2}H \\
  C: \\
  H: \\
  O: \\
 \]
2. \[
  4{(N{H_2})_2}CO \\
  N: \\
  C: \\
  O: \\
 \]
3. \[
  4{C_3}{H_5}{(OH)_3} \\
  C: \\
  H: \\
  O: \\
 \]

Answer 1

Hint: Atom, the smallest unit into which matter is often divided without the discharge of electrically charged particles. It is also the littlest unit of matter that has the characteristic properties of an element. As such, the atom is that the basic building block of chemistry. Calculate the number of atoms in one compound and then multiply by the number written to it or its coefficient.

Complete step-by-step answer:
1) Now let us look at the first part of the question which is \[5C{H_3}C{O_2}H\] now firstly count the number of atoms in \[C{H_3}C{O_2}H\] here let us count the number of carbons in this which is only \[2\], now count the number of hydrogen in it which is \[4\] ,now count the value of oxygen in it which is \[2\].
Now these values are for \[1\] molecule of \[C{H_3}C{O_2}H\] , for \[5C{H_3}C{O_2}H\] we have to multiply all atoms value by \[5\] as the \[5\]here is the coefficient. So values of \[C,H{\text{ and O}}\] in \[5C{H_3}C{O_2}H\] is
\[\
  C:10 \\
  H:20 \\
  O:10 \\
\ \]

2) Now second part of the question which is \[4{(N{H_2})_2}CO\] now firstly count the number of atoms in \[{(N{H_2})_2}CO\] here let us count the number of atoms in \[(N{H_2})\] here number of Nitrogen is \[1\] and number of hydrogen is \[2\]. But as we can see in the formula \[{(N{H_2})_2}CO\] the \[(N{H_2})\] part is twice so the values will be also twice which mean the number of Nitrogen in \[{(N{H_2})_2}CO\] is \[2\]and no. of hydrogen is \[4\] . Now let us count the value of carbon in formula \[{(N{H_2})_2}CO\] which is \[1\] and number of oxygen is also\[1\].
Now these values are for \[1\] molecule of \[{(N{H_2})_2}CO\] , for \[4{(N{H_2})_2}CO\] we have to multiply all atoms value by \[4\] as the \[4\] here is the coefficient. So values of \[C,N{\text{ and O}}\] in \[5C{H_3}C{O_2}H\] is
\[\
  N:8 \\
  C:4 \\
  O:4 \\
\ \]

3) Now the third part which is \[4{C_3}{H_5}{(OH)_3}\] now let us firstly count the number of atoms in one molecule of \[{C_3}{H_5}{(OH)_3}\] , Now let us firstly calculate the number of atoms in \[(OH)\]there is \[1\] atom of oxygen and \[1\] atom of hydrogen in it but in the formula \[{C_3}{H_5}{(OH)_3}\] the \[(OH)\] is thrice or three times so we have to multiply these values by so value of oxygen is \[3\] and value of hydrogen is \[3 + 5\] because \[3\] comes from the \[{(OH)_3}\] part and \[5\] comes from the remaining so the total number of hydrogen is \[8\].
Now the number of carbon is \[3\].
Now these values are for \[1\] molecule of \[{C_3}{H_5}{(OH)_3}\] , for \[4{C_3}{H_5}{(OH)_3}\] we have to multiply all atoms value by \[4\] as the \[4\] here is the coefficient. So values of \[C,H{\text{ and O}}\] in \[4{C_3}{H_5}{(OH)_3}\] is
\[\
  C:12 \\
  H:32 \\
  O:12 \\
\ \]


Note: Keep a check that the bracket in the formula is how many times then multiply all the no. of atoms in the bracket by that number. And after finding the number of atoms multiply it with its coefficient.