Question

solve the attachment​

Answer 1

$\displaystyle\huge\green{\underline{\underline{Question :-}}}$

A Compound contains 4.07% hydrogen,24.27% carbon and 71.65% chlorine. Its molar mass is 99 gram/mol. Find the molecular formula of it's compound?

$\displaystyle\huge\green{\underline{\underline{Answer :-}}}$

$\green{\huge\bold\\{<u>For\: Hydrogen\:,</u>}}$

→ Percentage = 4.07 %

→ Atomic weight = 1

→ Ratio = 4.07

→ Simple ratio = 2

$\green{\huge{\underline\bold\\{For\: Carbon\:,}}}$

→ Percentage = 24.4%

→ Atomic weight = 12

→ Ratio = 2

→ Simple ratio = 1

$\green{\huge\bold\\{For\: Chlorine\:,}}$

→ Percentage = 71.65%

→ Atomic weight = 35.5

→ Ratio = 2

→ Simple ratio = 1

$\huge\orange{\underline{{Now,}}}$

Empirical formula = CH2Cl

Molar mass = 98.96

Empirical formula weight = 49.5

$\huge\red{We\:know\:that\:,}$

$\:n\:=\:molar\:mass\:÷\:Empirical\:formula\:weight$

⠀= 98.96 / 49.5

⠀= 1.99

⠀≈ 2

$\huge\red{By\:using\:molecular\:formula,}$

$\:Molecular\:Formula\:=\:2\:×\: Empirical\:formula$

⠀= 2 × ( CH2Cl )

⠀= C2H4Cl2

∴ The required molecular formula of the compound is C2H4Cl2.

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Answer 2

Answer:

Calculate moles of each element - divide

% by atomic mass

C=19.998/12.011 = 1.665

H= 3.331/ 1.008 = 3.305

N= 23.320 / 14.007 = 1.665

O= 53.302 / 15.999 = 3.332

Divide through by smallest

C=1

H=2

N=1

O = 2 ( small rounding is accepted)

Empirical formula = CH2NO2

Formula mass = 12.011 +1.008'2 + 14.007 + 15.999:2 = 60.03 g/formula unit

Formula units in 1 molecule = 120.07 /

60.03 = 2

Molecular formula = ( CH2NO2)2 = C2H4N204 (1,2-dinitroethane.)