Search our library of Chemistry questions

Top answers

Chemistry

All levels

Explain why average bond enthalpies can be used for cyclohexane but not for benzene

Benzene has a resonance structure while cyclohexane consists of only single bonds of the same length. Benzene's resonance structure means it has intermediate bond lengths and strengths. This means aver...

Answered by Chloe M. • Chemistry tutor

3756 Views

Calculate the pH of a 4.00 x 10^-2 mol dm^-3 solution of Ba(OH)2

The easiest way to answer this question is by using the equation pH + pOH = 14.

Firstly, we need to work out the number of moles of OH^- in the solution. As the formula for Ba(...

Answered by Chloe M. • Chemistry tutor

13078 Views

Explain how the electron pair repulsion theory can be used to deduce the shape of, and the bond angle in, NH3.

Nitrogen has 5 valence electrons in its outer shell. Each Hydrogen has 1 valence electron in its outer shell, so the 3 Hydrogens donate 3 electrons in total. This gives 8 valence electrons in total. We...

Answered by Matthew N. • Chemistry tutor

9099 Views

Explain, in terms of sub-atomic particles, why the mass number of a magnesium atom is 24.

On the periodic table, Magnesium has the symbol ₁₂Mg²⁴, where 24 is the mass number and 12 is the atomic number. The atomic number is the number of protons found inside an atom, w...

Answered by Matthew N. • Chemistry tutor

23340 Views