Agaseous compound weighing 9.91582 g and occupying 1.312 x103 ml of volume at 98.7? c and 1023 torr of pressure is found by elemental analysis to be comprised of 6.2276 g c, 1.25382 g h, and 2.4344 g n – what is its molecular formula?

Molecular formula = C9H6N3

Explanation:

1. We have to change grams to mol:

C:

1 mol C = 12 g

6.2276 g C ×(1mol/ 12g)= 0.519 mol C

H:

1 mol H = 1 g

1.25382 g H ×(1mol / 1g)= 1.254 mol H

N:

1 mol N = 14 g

2.4344 g N ×(1mol/14 g)= 0.174 mol N

2. Then, you have to divide by smallest number of moles, it is 0.174. You have to approximate the values to integer numbers:

C:

0.519 mol C / 0.174 = 2.983 = 3

H:

1.254 mol H/ 0.174= 1.460 = 2

N:

0.174 mol N/0.174= 1

With this numbers, we obtain the empirical formula C3H2N. Now we gonna calcualte the molecular formula with the empirical formula:

3. Find the molecular weith of empirical formula:

C3 = 12 x 3 = 36

H = 2

N = 14

C3H2N = 36 +2 +14 =52 g/mol

4. Then you have to divide the molecular formula molar mass over the empirical formula mass:

molecular formula molar mass / empirical formula molar mass

To find the molecular formula mass we have to use the ideal gas equation:

PV=nRT

Where:

P= 1023 torr

V = 1.312 ×103 mL

n = mol

R = 0.0821 atmL /molK

T = 98.7 °C

Remeber you have to use the right units for the data, so we gonna change torr to atm, and mL to L and °C to K:

P = 1.35 atm

V = 1.312 L

T = 371.85 K

And replace in the equation:

PV=nRT

1.35 atm ×1.312 L = n ×0.3821×0.0821 atmL/molK ×371.85K

1.784 atmL= n ×30.53 atmL/mol

n= 0.058 mol

And to find the molecular formula molar mass we have to divide de mol n over the grams given on the excersice 9.91582 g:

9.91582g / 0.082 mol = 170.96 g/mol

And now we can use the formula, and the result has to be approximate to a integer number:

molecular formula molar mass / empirical formula molar mass  = 3.29 = 3

5. Multiply the whole number with the subscripts of the empirical formula:

C3×3H2×3N1×3 = C9H6N3

To see all the problem solve, with the mathematics explained deeply, please watch the document attached.

Molecular formula = C9H6N3

a is the answer to this question

explanation:

plants need sunlight, water, and carbon dioxide to make food. plants use the raw materials of water, nutrients they absorb from soil, and carbon dioxide to make sugars the plant can use. energy from the sun and chlorophyll are also needed.