please answer my question as soon as possible i have my exams tomorrow a)Combustion of 0 2000g of vitamin - Chemistry - Some Basic Concepts of Chemistry

Question

please answer my question as soon as possible i have my exams
tomorrow
a)Combustion of 0 2000g of vitamin C gives 0 2998g of CO2
and 0 819g of H2O What is the empirical formula of vitamin
C?
b)4 litres of water are added to 2L of 6 molar HCl solutions
What is the molarity of resulting solution?

Shikha Aggarwal · Accepted Answer

a)
Mass of water produced in this reaction must be 0 0819g and not 0
819g
Given that vitamin C on combustion gives carbon dioxide and water
Let vitamin C is X
X (s) + O2(g) →CO2â€‹
(g) + H2O (l)
0 2000 g 0 2998g 0 0819g

Molar mass of CO2 = 12 +
2×16= 44 g
Amount of carbon in 44 g CO2 = 12 g
â€‹Amount
of carbon in 0 2998g CO2 = 1244×0 2998 gâ€‹ =0 0818
g

Molar mass of H2O =
1×2 + 16= 18 g
Amount of hydrogen in 18 g H2Oâ€‹ = 2 g
â€‹Amount
of hydrogen in 0 0819 g H2Oâ€‹ = 218×0 0819
gâ€‹ =0 0091
g

Percentage of carbon in fuel gas = 0
08180 2000×100 = 40 9
%

Percentage of hydrogen in compound
= 0 00910 2000×100 = 4
55 %â€‹

Thus Percentage of oxygen in the compound= 100 - (40 9 + 4 55) = 54
55 %

Element
Atomic mass of element
Percentage
Moles of the constituents
Molar ratio
Simple whole number ratio

C
12
40 9
40 912=3 408

3 4083 408=1
1×3=3

H
1
4 55
4 551=4 55
4 553 408=1 33

1 33×3=4

O
16
54 55

54 5516=3 41
3 413 408=1 00
1×3=3

Thus the simple ratio of
C:H:O is
3:4:3

Thus empirical formula of
the compound =
C3H4O3

b)
First we find that how many moles of HCl are there,We know, Molarity=  Moles of soluteVolume of solution in LitreNow it is given that Molarity = 6MVolume= 2 LThus 6=Moles of HCl2⇒Moles of HCl = 6×2 = 12 molesNow 4 L of water is added to the solution therefore now the total volume of solution becomes 2+4 =6LBut Number of moles of HCl remain same Thus, now 12 moles of HCl are present in 6 L solution
Therefore molarity becomes:Molarity=  Moles of HClVolume of solution in LitreMolarity=  12 moles6 L             =2 M
Thus now the molarity of the solution is 2 M

Element	Atomic mass of element	Percentage	Moles of the constituents	Molar ratio	Simple whole number ratio
C	12	40.9	$\frac{40.9}{12} = 3.408$	$\frac{3.408}{3.408} = 1$	$1 \times 3 = 3$
H	1	4.55	$\frac{4.55}{1} = 4.55$	$\frac{4.55}{3.408} = 1.33$	$1.33 \times 3 = 4$
O	16	54.55	$\frac{54.55}{16} = 3.41$	$\frac{3.41}{3.408} = 1.00$	$1 \times 3 = 3$

please answer my question as soon as possible. i have my exams tomorrow a)Combustion of 0.2000g of vitamin C gives 0.2998g of CO2 and 0.819g of H2O. What is the empirical formula of vitamin C? b)4 litres of water are added to 2L of 6 molar HCl solutions. What is the molarity of resulting solution?