1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Vsevolod [243]
3 years ago
9

A 10.0 g sample of an unknown liquid is vaporized at 120.0°C and 5.0 atm. The volume of the vapour is found to be 568.0 mL. The

liquid is determined to be made up of 84.2% carbon and 15.8% hydrogen. What is the molecular formula for the liquid?
Chemistry
1 answer:
Minchanka [31]3 years ago
6 0

Answer:

molecular formula of liquid = C₈H₁₈

Explanation:

First we determine the empirical formula of the liquid:

Number of moles of each element present in the liquid = % mass / molar mass

For Carbon, (molar mass = 12.01 g/mol) : 84.2/12.01 =7.011 moles

For Hydrogen (molar mass = 1.01 g/mol) : 15.8/1.01 = 15.643

Simplest mole ratio of the elements, C : H  is given by:

C = 7.011/7.011 = 1.0

H = 15.643/7.011 = 2.23

Multiplying through with 5, C:H = 5:11

Therefore, empirical formula is C₅H₁₁

The molecular mass of the liquid is next determined:

Using PV = nRT to find the number of moles of the liquid present

P = 5.0 atm; V = 568.0 mL = 0.568 L; R = 0.082 L*atmmol⁻¹ K⁻¹; T = 273 + 120 = 393 K

n = PV/RT = (5*0.568)/0.082*393

n = 0.088 moles

Molar mass of liquid = mass/no of moles = 10.0 g/ 0.088 moles = 113.63 gmol⁻¹

Molecular formula = n(empirical formula)

Molar mass of empirical formula, C₅H₁₁ = 71 gmol⁻¹

n = molecular mass/empirical mass = 113.63/71 = 1.6

Therefore, molecular formula =  1.6*(C₅H₁₁) = C₈H₁₈

You might be interested in
What color does red litmus paper turn in an acid base and neutral solution?
quester [9]
<span> red litmus paper turns </span>blue <span>under basic or alkaline conditions, with the color change occurring over the pH range 4.5–8.3 at 25 °C (77 °F). Neutral litmus paper is purple.</span>
6 0
3 years ago
Read 2 more answers
9. At equilibrium a 2 L vessel contains 0.360
klio [65]

Answer:

Ke = 34570.707

Explanation:

  • H2(g) + Br2(g) → 2 HBr(g)

equilibrium constant (Ke):

⇒ Ke = [HBr]² / [Br2] [H2]

∴ [HBr] = (37.0 mol) / (2 L) = 18.5 mol/L

∴ [Br2] = (0.110 mol) / (2 L) = 0.055 mol/L

∴ [H2] = (0.360 mol) / (2 L) = 0.18 mol/L

⇒ Ke = (18.5 mol/L)² / (0.055 mol/L)(0.18 mol/L)

⇒ Ke = 34570.707

3 0
3 years ago
For the simple decomposition reactionAB(g)→ A(g) + B(g)Rate =k[AB]2 and k=0.2 L/mol*s . How long will it takefor [AB] to reach 1
mixer [17]

Answer:

6.66 s will it take for [AB] to reach 1/3 of its initial concentration 1.50 mol/L.

Explanation:

Rate = k[AB]^2

The order of the reaction is 2.

Integrated rate law for second order kinetic is:

\frac{1}{[A_t]} = \frac{1}{[A]_0}+kt

Where, [A_0] is the initial concentration  = 1.50 mol/L

[A_t] is the final concentration  = 1/3 of initial concentration = \frac{1}{3}\times 1.50\ mol/L = 0.5 mol/L

Rate constant, k = 0.2 L/mol*s

Applying in the above equation as:-

\frac{1}{0.5} = \frac{1}{1.50}+0.2t

\frac{1}{1.5}+0.2x=\frac{1}{0.5}

t = 6.66\ s

<u>6.66 s will it take for [AB] to reach 1/3 of its initial concentration 1.50 mol/L.</u>

5 0
3 years ago
Why does magma composition change during fractional crystallization?.
katrin [286]
Why does magma composition change during fractional crystallization? Different elements in the magma form crystals at different rates, leaving behind more of the unused elements. ... The crystals are denser than the magma.
6 0
2 years ago
Is zinc a basic radical or acid radical?​
lukranit [14]

Answer:

depends on the element it's reacting with..

Explanation:

if the another element requires less energy to loose electron then zinc will become negatively charged and hence becomes acidic radical..

normally if it is reacting with element with valency 4 and Atomic number less than it(Ti,Si,C) then it will lose electron and gain positive sign and henve becomes basic radical..

6 0
3 years ago
Other questions:
  • Al-Qaeda is the name of the group that fought against the Soviet-supported government in Afghanistan.
    11·1 answer
  • When you hear the word solution, you tend to think of a liquid. However, a solution can be a homogeneous mixture of any phase. T
    15·1 answer
  • Increasing the concentration of a reactant shifts the position of a chemical equilibrium towards formation of more products. wha
    13·1 answer
  • Which is NOT a physical property?
    7·2 answers
  • Compare and contrast the Ionization energies of groups 1&amp;2 (Alkali and Alkaline metals) with the Ionization energies of grou
    7·1 answer
  • 1. What is the symbol for atomic mass? What are the units of atomic mass in terms of atoms? 2. What is the symbol for molar mass
    14·1 answer
  • Atoms are:
    14·1 answer
  • Use the drop-down menus to match the name and structure for the following cycloalkanes. A five-sided polygon. A square. A five-s
    6·1 answer
  • El agua de lluvia tiene un pH de 4,00. Calcule su concentración de ion hidrógeno en mol/litro. Explique por qué el agua es ácida
    6·1 answer
  • What is it about water that makes it able to dissolve both polar covalent and iconic substances
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!