Calculate the molar mass of the following substances.
(a) Ethyne, `C_(2)H_(2)`
(b) Sulphur molecule, `S_(8)`
(c) Phosphorus molecule, `P_(4)` (Atomic mass of phosphorus = 31)
(d) Hydrochloric acid, HCl
(e) Nitric acid, `HNO_(3)`

Explanation

(A) Ethyne, `C_(2)H_(2)`
Molar mass of `C_(2)H_(2)`=`=(2xx"Aromic mass of C")+(2xx"Atomic mass of H")`
`=(2xx12u)+(2xx1u)=26u`
(b) Sulphur molecule, `S_(B)`
`"Molar mass of "S_(B)=8xx"Atomic mass of S"=(8xx32u)=256u`
(c )Phosphorus molecule, `P_(4)`
`"Molar mass of "P_(4)=4xx"Atomic mass of P"=(4xx31u)=124u`
(d) Nitric acid, `HNO_(3)`
`"Molar mass of "HNO_(3)=(1xx"Atomic mass of H")+(1xx"Atomic mass of N")+(3xx"Atomic mass of O")`
`=(1xx1u)+(1xx35.5u)=36.5u`