Search our library of homework questions

Top answers

All subjects

All levels

Calculate the empirical and molecular formula of the molecule giving rise to the molecular ion peak at 148 m/z. The percentage composition by weight is 64.80 % carbon, 13.62 % hydrogen, and 21.58 % oxygen

Step 1, pick out the important information from the question: Carbon: Hydrogen: Oxygen % by weight: 64.8: 13.62: 21.58 Step 2, from the periodic table, find out the relative atomic masses of each element:...

Answered by Olivia H. • Chemistry tutor

5702 Views

Write x^2 - 6x +7 in the form (x+a)^2 +b

Follow standard procedure that can be taught on a whiteboard. In general:ax^2 + bx + c = (x+b/2)^2 - (b/2)^2 + csox^2 - 6x + 7 = (x-3)^2 - (9) + 7= (x-3)^2 - 2

Answered by James C. • Maths tutor

4225 Views

To what extent were the Atlantic Revolutions inspired by Enlightenment political ideas?

Equal rights for man were key political Enlightenment ideas that were pivotal to the American and Haitian Revolutions. These ideas were underpinned in Rousseau’s ‘Social Contract’[1] (Appendix, Sou...

Answered by Blayne S. • History tutor

4425 Views

Define an obtuse angle.

An angle between 90 degrees and 180 degrees. NB- a reflex angle is an angle between 180 degrees and 360 degrees.

Answered by Roshini M. • Maths tutor

2791 Views

Sketch the curve with the equation y=x^2 +4x+4, labelling the points where it crosses or touches the axes.

The curve is a quadratic equation because it has a x^2 - as it is positive it will be a u shaped parabola. The equation can be factorised by thinking of two numbers which add to make 4 (the b value) and m...

Answered by Sophia S. • Maths tutor

3373 Views