1) chemical analysis of a gaseous compound show its composition to be 36.4% carbon, 57.5% fluorine, and 6.1%
hydrogen. a sample of 1.00 l of this gas has a mass of 2,96 g. what molecular formula do these data suggest for
this compound?

2)analysis of a compound shows that it consists of 24.3% carbon, 4.1% hydrogen, and 71.6% chlorine. the molecular
mass of the compound is determined to be 99.8 g/mol. what molecular formula corresponds to these data?

3)chemical analysis of a gaseous compound show its composition to be 36.4% carbon, 57.5% fluorine, and 6.1%
hydrogen. a sample of 1.00 l of this gas has a mass of 2,96 g. what molecular formula do these data suggest for
this compound?

1.  Empirical formula =  CFH₂

   Molecular formula = C₉F₉H₁₈  

2. Empirical formula is  CH₂Cl

   Molecular formula = C₂H₄Cl₂

3. Empirical formula =  CFH₂

   Molecular formula = C₉F₉H₁₈

Explanation:

1) Given data

  Percentage of carbon= 36.4%

  Percentage of fluorine  = 57.5%

  Percentage of hydrogen = 6.1%

  mass = 296 g

  Empirical formula = ?

  Molecular formula  = ?

Solution:

Number of gram atoms of C = 36.4/12 = 3.03

Number of gram atoms of F = 57.5/19 = 3.03

Number of gram atoms of H = 6.1/ 1 = 6.1

Atomic ratio:

    C              :            F             :    H

3.03/3.03      :       3.03/3.03    :   6.1/3.03

    1                :            1              :     2 

      C : F : H = 1 : 1 : 2

Empirical formula is  CFH₂

Now we calculate Molecular formula

   Molecular formula = n (empirical formula)

   n = molar mass of compound / empirical formula mass

   n = 296  / 32

   n = 9.25 we take it as 9

    Molecular formula = n (empirical formula)

    Molecular formula = 9 ( CFH₂)

  Molecular formula = C₉F₉H₁₈

Check the answer by calculating the molecular mass, it should be almost 296 g.

   Molecular formula = C₉F₉H₁₈

   molecular mass = 12 (9) + 18.998 (9) + 1 (18)

   molecular mass = 108 +  170.98 + 18

   molecular mass = 296.98 g/mol

2) Given data

   Percentage of carbon= 24.3%

   Percentage of hydrogen  = 4.1%

   Percentage of chlorine = 71.6%

   molecular mass = 99.8 g/mol

   Molecular formula  = ?

Solution:

Number of gram atoms of C = 24.3/12 = 2

Number of gram atoms of H = 4.1/1 = 4.1

Number of gram atoms of Cl = 71.6/35.5 = 2

Atomic ratio:

    C         :      H        :    Cl

    2/2      :       4/2    :   2/2

    1          :      2        :     1 

      C : H : Cl = 1 : 2 : 1

Empirical formula is  CH₂Cl

Now we calculate Molecular formula

   Molecular formula = n (empirical formula)

   n = molar mass of compound / empirical formula mass

   n = 99.8  / 49.5

   n = 2.02 we take it as 2

   Molecular formula = n (empirical formula)

    Molecular formula = 2 ( CH₂Cl)

  Molecular formula = C₂H₄Cl₂

Check the answer by calculating the molecular mass, it should be almost 99.8 g.

   Molecular formula = C₂H₄Cl₂

   molecular mass = 12 (2) + 1 (4) + 2 (35.5)

   molecular mass = 24 +  4 + 71

   molecular mass = 99 g/mol

3) Given data

  Percentage of carbon= 36.4%

  Percentage of fluorine  = 57.5%

  Percentage of hydrogen = 6.1%

  mass = 296 g

  Empirical formula = ?

  Molecular formula  = ?

Solution:

Number of gram atoms of C = 36.4/12 = 3.03

Number of gram atoms of F = 57.5/19 = 3.03

Number of gram atoms of H = 6.1/ 1 = 6.1

Atomic ratio:

    C              :            F             :    H

3.03/3.03      :       3.03/3.03    :   6.1/3.03

    1                :            1              :     2 

      C : F : H = 1 : 1 : 2

Empirical formula is  CFH₂

Now we calculate Molecular formula

   Molecular formula = n (empirical formula)

   n = molar mass of compound / empirical formula mass

   n = 296  / 32

   n = 9.25 we take it as 9

    Molecular formula = n (empirical formula)

    Molecular formula = 9 ( CFH₂)

  Molecular formula = C₉F₉H₁₈

Check the answer by calculating the molecular mass, it should be almost 296 g.

   Molecular formula = C₉F₉H₁₈

   molecular mass = 12 (9) + 18.998 (9) + 1 (18)

   molecular mass = 108 +  170.98 + 18

   molecular mass = 296.98 g/mol

answer; i believe that the correct answer is (a) potassium(k)

for step 7 table c on the lab "newtons law of action"   the average time it took the car to travel .25 meters   was 1.92 seconds.

the average time it took the car to travel 0.50 meters was 2.61 seconds

hope this : )