Problem 52 - Chemistry: The Central Science

Question

How many hydrogen atoms are in each of the following: (a) \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\), (b) \(\mathrm{Ca}\left(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{COO}\right)_{2}\), (c) \(\left(\mathrm{NH}_{4}\right)_{3} \mathrm{PO}_{4}\) ?

Step-by-Step Solution

Answer

In conclusion, the number of hydrogen atoms in each formula is: (a) \(C_2H_5OH\): 6 hydrogen atoms, (b) \(Ca(C_2H_5COO)_2\): 12 hydrogen atoms, (c) \((NH_4)_3PO_4\): 12 hydrogen atoms.

Step 1: Understand the chemical formulas

In a chemical formula, each element is represented by its symbol and a number subscript. If no number is present (just the symbol), it means there is only one atom of that element in the molecule. For example, in the formula C2H5OH, there are 2 Carbon atoms, 5 Hydrogen atoms, and 1 Oxygen atom followed by 1 Hydrogen atom.

Step 2: Calculate the hydrogen atoms for each formula

(a) \(C_2H_5OH\) In this formula, there are 5 Hydrogen atoms in the C2H5 group and 1 Hydrogen atom in the OH group. Total hydrogen atoms = 5 + 1 = 6 (b) \(Ca(C_2H_5COO)_2\) In this formula, the term within the parentheses is repeated 2 times due to the subscript '2'. So, let's calculate the hydrogen atoms in one (C2H5COO) group first: There are 5 Hydrogen atoms in the C2H5 group and 1 Hydrogen atom in the COO group. Total hydrogen atoms in one group = 5 + 1 = 6 Since there are 2 such groups: Total hydrogen atoms in the whole formula = 6 * 2 = 12 (c) \((NH_4)_3PO_4\) In this formula, the term within the parentheses is repeated 3 times due to the subscript '3'. The NH4 group contains 4 Hydrogen atoms. Since there are 3 such groups: Total hydrogen atoms in the whole formula = 4 * 3 = 12

Step 3: Present the final answer

In conclusion, we have the following number of hydrogen atoms in each formula: (a) C2H5OH: 6 hydrogen atoms, (b) Ca(C2H5COO)2: 12 hydrogen atoms, (c) (NH4)3PO4: 12 hydrogen atoms.