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What is the C-O-H bond angle in propan-2-ol and why is this? [4 marks]

The bond angle is 104.5 degrees. This is because of the pairs of electrons around the oxygen atom: it has 2 bonded pairs and 2 lone pairs. Lone pairs and bonded pairs of electrons repel each other. However a...
AC
Answered by Adam C. • Chemistry tutor
18390 Views

How to complete the square to find the value of x?

To complete the square you compare your equation in the form x 2 + bx + c = 0 to a similar equation of (x + b/2) 2 + c = 0 . From expanding out the second equation we have x 2 + bx + (b/2) 2 + c = 0 we can s...
AA
Answered by Ayotunde A. • Maths tutor
3960 Views

How can the trapezium rule be used to estimate a definite integral?

Are we comfortable with an integral being the area under a curve on a graph? Well we'll draw a curve and think about how we could estimate this area. Would you agree that we could chop up the area under the ...
JS
Answered by Joseph S. • Maths tutor
3511 Views

Factorise x^2 -7x+10, and hence solve x^2-7x+10=0

Firstly, it is important to recognise that the answer will need to be in the form of two pairs of brackets because the question is asking us to factorise a quadratic equation. The equation only has a single ...
GT
Answered by Gareth T. • Maths tutor
6554 Views

How do you know if a noun is feminine and needs la' before it or if a noun is masculine and needs 'le'?

This is one of those questions that doesn't have a straightforward answer and it is only through experience of the language that one learns the gender of each noun. However, there are some noun endings that ...
NG
Answered by Natasha G. • French tutor
2363 Views