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10cm^3 of 1M NaOH solution is mixed with 15cm^3 of 0.5M HCl, what is the resulting pH of the solution?

Step 1: Work out the moles of NaOH and HCl added into the solution 10cm^3 of 1M NaOH would mean that there is 10cm^3/1000cm^3 x 1M present, i.e. 0.01 moles 15cm^3 of 0.5M HCl would mean that there ...

Answered by Lachlan A. • Chemistry tutor

9749 Views

How was the quadratic formula obtained.

We want a solution to ax^2+bx+c=0. Complete the square to get a[(x+b/2a)^2 -(b^2)/(4a^2)]+c=0. Expalding brackets and rearanging gets a(x+b/2a)^2=(b^2)/4a -c. Divide by a to get (x+b/2a)^2= b^2/4a^2 -c/a=...

Answered by Jon H. • Maths tutor

3890 Views

How many hours revision should I do between now and my exam? Can I have help coming up with a plan?

Let’s break this down. Let’s look at how much time you have before the exam and work out something manageable, because overwhelming yourself with too much revision can be counter productive.

Answered by Rose M. • English Literature tutor

4713 Views

How do you do well in an AQA GCSE English Literature exam?

First thing’s first, let’s take a look at the AQA mark scheme, because that is what your marker will be following when they get your completed paper. The first thing they talk about in their mark scheme i...

Answered by Rose M. • English Literature tutor

12437 Views

Prove that (sinx)^2 + (cosx)^2 = 1

We start with the definitions of sine and cosine, which are, respectively: sinx = opposite/hypoteneuse and cosx = adjacent/hypoteneuse. We then square the analyzed expressions to get the following:
...

Answered by Eno A. • Maths tutor

14242 Views