MYTUTOR SUBJECT ANSWERS

360 views

The ratio between the molar mass of an alkene(A) and an alkyne(B) with the same number of carbon atoms is 1.05. Find the molecular formulas of the two hydrocarbons then write the reaction for how we can obtain the alkene A from the alkyne B.

We start by remembering the general formulas of alkenes and alkynes:

Alkenes - CnH2n

Alkynes - CnH2n-2

We calculate the molar mass of both of these using the fact that the atomic mass of carbon is 12 and for hydrogen 1 :

 μA=12n+2n=14n grams/mole

 μB=12n+2n-2=14n-2 grams/mole

The ratio then becomes:

μ/ μB=1.05

14n / 14n - 2 = 1.05

14n =(14n - 2) * 1.05

14n = 14.7n - 2.1

14.7n - 14 = 2.1

0.7n = 2.1

n = 3

Therefore, our hydrocarbons are:

A = C3H6 - propene  

B = C3H4 - propyne

The reaction to obtain propene from the propyne is:

CH≡C-CH3 + H2 --Ni---> CH2=CH-CH3

The reaction is a hydrogenation one and the condition needed for it Nickel.

Cosmin B. A Level Maths tutor, GCSE Maths tutor, GCSE Computing tutor...

1 year ago

Answered by Cosmin, an A Level Chemistry tutor with MyTutor


Still stuck? Get one-to-one help from a personally interviewed subject specialist

96 SUBJECT SPECIALISTS

£22 /hr

Kyna F.

Degree: Materials Engineering (Masters) - Exeter University

Subjects offered:Chemistry, Science+ 2 more

Chemistry
Science
Maths
-Personal Statements-

“About me Hello, my name is Kyna and I'm a second year Materials Engineering student studying at theUniveristy of Exeter. I have always had a love for all things science and maths, and would love to help any students in need of extra s...”

£20 /hr

Hilary L.

Degree: Veterinary Medicine & Surgery (Bachelors) - Glasgow University

Subjects offered:Chemistry, Biology+ 1 more

Chemistry
Biology
-Personal Statements-

“Hello! I'm Hilary, a 1st year veterinary student at the University of Glasgow. I am a recent May 2016 IB diploma graduate, attaining a total of 40 points with a 7 in HL biology. This means that I am familiar with the recent change of t...”

£24 /hr

Tiarnan B.

Degree: MChem (Masters) - York University

Subjects offered:Chemistry, Maths+ 2 more

Chemistry
Maths
Geography
-Personal Statements-

“I am a fun, open and qualified tutor. I guarantee by choosing me you will reach where you want to be and beyond, all while enjoying the subject!”

About the author

Cosmin B.

Currently unavailable: for regular students

Degree: Computer Science (Bachelors) - University College London University

Subjects offered:Chemistry, Maths+ 1 more

Chemistry
Maths
Computing
-Personal Statements-

“I am currently a Computer Science student at University College London. I have always had a passion for science and technology  and I hope that I can share it with everyone else through my tutoring sessions. I am a calm and friendly p...”

You may also like...

Posts by Cosmin

How can we calculate the derivative of function f(x)= (x+2)/(x-1)?

How can we solve a two-equation, two-unknown values?

How can we write a C++ program to add two numbers?

The ratio between the molar mass of an alkene(A) and an alkyne(B) with the same number of carbon atoms is 1.05. Find the molecular formulas of the two hydrocarbons then write the reaction for how we can obtain the alkene A from the alkyne B.

Other A Level Chemistry questions

What are the differences between covalent and ionic bonding?

How do buffers work?

What evidence is there to support the delocalised model of benzene over Kekulé's model?

Describe chemical test/s you could use to determine the identity of a carbonyl compound.

View A Level Chemistry tutors

We use cookies to improve your site experience. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok