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Why does the pH of neutral water drop when it is left out in an uncovered container on a worktop for a long period of time?

This question tests your knowledge on; the properties of non-metal oxides in solution, the concept of equilibrium, pH. Non-metal oxides such as (CO2, P4O10, SO2, etc) are acidic in solution. When left out on...
NG
3220 Views

Using the quadratic formula factorise 2x^2 + 7x + 11 =0

Using the substitutions a=2, b=7 and c=11 with the quadratic formula we get two values of x at 3.39 and 0.89.
EA
Answered by Emily A. • Maths tutor
6961 Views

What are partial fractions for and how do I find them?

Being able to find partial fractions is very useful for complex algebraic fractions that cannot be intergrated in their current form. Breaking it down into a sum of it's partial fractions gives two (or more)...
CT
Answered by Christine T. • Maths tutor
4459 Views

What specialised structures do the lungs have to allow diffusion of gases?

The lungs are highly specialised. They have alveoli which are small air sacs. Alveoli give the lungs a big surface area, meaning that more oxygen can diffuse from the lungs into the blood stream, and more wa...
BH
Answered by Bethany H. • Biology tutor
15099 Views

What is the subjunctive and when should I use it?

The subjunctive is what we call a 'mood', which is a verb form conveying the attitude of the speaker. By now, you'll be used to employing the indicative mood, which we use to convey facts or statements the s...
RA
Answered by Rowan A. • French tutor
2684 Views