Top answers

Write equations and give the mechanism for the reaction of butanone with: 1) NaBH4 and 2) HCN

The first thing we need to do in this type of organic chemical reaction, is identify our electrophiles and nucleophiles. We know that due to the electronegativity of the oxygen atom in carbonyl compounds tha...
HS
Answered by Harry S. • Chemistry tutor
7257 Views

Explain why the amount of solar radiation absorbed by the earth's surface varies from place to place.

Land covered in concrete and buildings alters the albedo of a pace because dark colours will absorb, rather than reflect incoming sunlight. This creates 'urban heat islands' where temperatures are higher whe...
AS
Answered by Alice S. • Geography tutor
9688 Views

How should I structure an essay in an exam?

When writing an essay in an exam, try to ensure that your answer is focused, well structured and supported by evidence. To start with, it is a good idea to create a brief plan for your essay. This should inc...
CK
Answered by Charlotte K. • History tutor
3276 Views

How can I calculate the maximum value of the compound angle formulae Rsin(x+a) and Rcos(x+a)?

Often, the compound angle formulae can seem quite offputting, especially since exam pressures can mean the random "R" at the front of an angle addition formulae appears confusing. However, finding ...
LB
Answered by Luke B. • Maths tutor
16229 Views

How do I work out the nth term?

The nth term falls into the topic of linear sequences . A linear sequence is a set of numbers (such as "1, 2, 3, 4, ...") that are connected by a rule , which applies to every number in the sequenc...
LB
Answered by Luke B. • Maths tutor
193956 Views