Search our library of Chemistry questions

Top answers

Chemistry

All levels

What is fractional distillation used for in industry? Explain the molecular basis behind it.

Separating different sized hydrocarbons (from crude oil)Different length hydrocarbons have different strength VDW forces between their moleculesTherefore longer length hydrocarbons have stronger VDW force...

Answered by Nick G. • Chemistry tutor

2432 Views

There are three halogenoalkanes with halogens F, Br and I. Each undergo an SN2 reaction. How does the rate of reaction differ between the three halogenoalkanes?

The Iodoalkane will have the fastest rate of reaction. The Bromoalkane will have the second fastest, while the Floroalkane will have the slowest. This is because the atomic radius increases from Florine t...

Answered by Rosalie G. • Chemistry tutor

3217 Views

What happens upon the addition of NaOH solution (OH- ions) to a pink solution of cobalt chloride? Include equation(s) in your answer.

A blue precipitate is formed when both a few drops, or excess, of NaOH is added to a solution of cobalt chloride; this is an example of an acid-base chemical reaction.The relevant equation is: [Co(H_2...

Answered by Carolina W. • Chemistry tutor

10311 Views

The student did another experiment using 20 cm3 of sodium hydroxide solution with a concentration of 0.18 mol/dm3 . Relative formula mass (Mr) of NaOH = 40 Calculate the mass of sodium hydroxide in 20 cm3 of this solution.

20/1000 *0.18
final answer 0.144 Answer must be explained in person. It is very difficult to explain in writing.

Answered by Saranya G. • Chemistry tutor

4836 Views

Why is there a significant difference between the radii of first and second row transition metals, where as no difference (or even a decrease) is observed between the second and third rows?

The answer stems from the lanthanide (or lanthanoid) contraction. In more detail, there is a steady decrease in the radii of atoms from Lanthanum through to Lutetium, despite the associated increase in th...

Answered by Ioannis B. • Chemistry tutor

2435 Views