Mixture......................
Given the percentage composition of HC as C → 81.82 % and H → 18.18 %
So the ratio of number if atoms of C and H in its molecule can will be:
C : H = 81.82 12 : 18.18 1 C : H = 6.82 : 18.18 = 6.82 6.82 : 18.18 6.82 = 1 : 2.66 ≈ 3 : 8
So the Empirical Formula of hydrocarbon is:
C 3 H 8
As the mass of one litre of hydrocarbon is same as that of C O 2 The molar mass of the HC will be same as that of C O 2 i.e 44 g mol
Now let Molecular formula of the HC be ( C 3 H 8 ) n
Using molar mass of C and H the molar mass of the HC from its molecular formula is:
( 3 × 12 + 8 × 1 ) n = 44 n So 44 n = 44 ⇒ n = 1
Hence the molecular formula of HC is C 3 H 8
Does that help?
Answer:
THE LENGTH OF THE AIR COLUMN IS 9.5 CM
Explanation:
Taking the atmospheric pressure to be 760 mmHg;
When the capillary tube is held horizontally, the pressure of the tube is 760 mmHg
when the capillary tube is held vertically, the pressure increases by 4 cm = 40 mm
The new pressure of the tube is hence, 760 + 40 mmHg = 800 mmHg
Using the pressure forlmula;
P1 V1 = P2 V2
P1 A1 L1 = P2 A2 L2
where A1 and A2 is the area of the capillary tube and it is equal, it cancels out.
P1 l1 = P2 l2
l2 = P1 l1 / P2
l2 = 760 * 10 / 800
l2 = 9.5 cm
The length of the air in the tube is 9.5 cm.
