Question

Match the given compounds with their molecular mass:

• A. i. 158u
• B. ii. 74.5u
• C. iii. 18u
• D. iv. 30u

Answer 1

a. KCl - K(potassium) has mass 39, Cl(chlorine) has mass 35.5, So molecular mass is 39 + 35.5 = 74.5u
b. $C_2{H}_6–C$ (carbon) has mass 12, H(hydrogen) has mass 1, 12 × 2 = 24; 6 × 1 = 6 molar mass = 30u
c. $KMn{O}_4–K$ (potassium) has mass 39, Mn(manganese) has mass 55, O(oxygen) has mass 16; 39 + 55 + 4 × 16 = 158u
d. $H{2}_O-H$ (hydrogen) has mass 1, O(oxygen) has mass 16; 1 × 2 + 16 = 18u