Search our library of Chemistry A Level questions

Top answers

Chemistry

A Level

Can you explain what stoichometry actually is and why the ratio is not the same as the number of moles?

Stoichiometry is just a way of relating two species that react, in a ratio. EXAMPLE: 1A + 2B -> 3C Now usually this would be written as A + 2B -> 3C but I've written the 1 to exaggerate the point. N...

Answered by Michael R. • Chemistry tutor

5210 Views

0.250 g of a hydrocarbon known to contain carbon, hydrogen and oxygen was subject to complete combustion and produced 0.3664 g of CO2 and 0.1500 g of H2O. What is the empirical formula of this hydrocarbon?

The first step here is to determine the mass of C in CO₂ and the mass of H in H₂O. This is done by dividing the relative atomic mass, Mr, by the relative molecular mass of the com...

Answered by Joshua H. • Chemistry tutor

11813 Views

1.5 g of hydrocarbon undergoes complete combustion to give 4.4 g of CO2 and 2.7 g of H2O. Given this data, what is the empirical formula of this hydrocarbon?

The first step here is to determine the mass of C in CO₂ and the mass of H in H₂O. This is done by dividing the atomic mass by the molecular mass and then multiplying by the mass ...

Answered by Joshua H. • Chemistry tutor

82960 Views

Why is phenol more reactive than benzene?

Phenol (which is a benzene ring with one substituted carbon with a hydroxyl or alcohol group) does not require a halogen carrier to be halogenated whereas benzene itself cannot react with a halogen alo...

Answered by Thomas N. • Chemistry tutor

36020 Views

What is the difference between a nucleophile and an electrophile?

A nucleophile is a molecule or ion that donates a pair of electrons to form a new covalent bond. It is strongly attracted to a region of positive charge. Common nucleophiles include hydroxide ions; due...

Answered by Liam M. • Chemistry tutor

21082 Views