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Chemistry

A Level

A buffer solution is made with a pH of 5.000. Solid sodium ethanoate, CH3COONa, is added to 400 cm^3 of 0.200 mol dm^–3 ethanoic acid (Ka = 1.75 × 10^–5 mol dm^–3). Calculate the mass of sodium acetate that must be dissolved in the acid to prepare this

There are three steps:
Calculate [CH₃COO^–] using the equation for K_aCalculate the moles of CH₃COO^– using the equation concentration = moles/volu...

Answered by Felix B. • Chemistry tutor

13673 Views

Explain the trend in melting points of the period 3 elements

There are four main areas we need to consider in answering this question. The first is Sodium, Magnesium and Aluminium. These are all metals and so have a metallic bonding structure. As you go across the ...

Answered by Lloyd M. • Chemistry tutor

46420 Views

Can you explain the bond angle and shape of the molecule NH3?

In NH3, the nitrogen atom is bonded to three hydrogen atoms. By drawing the Lewis structure, the central nitrogen atom shows 3 covalent bonds to hydrogen and one lone pair. Valence Shell Electron Pair Rep...

Answered by Jenny J. • Chemistry tutor

13146 Views

What is the geometry of a BF3 molecule?

The molecule is 'trigonal planar'.This is because the central atom, boron, is attached to three fluorine atoms, and each fluorine atom repels the other fluorine atoms as much as possible. The only configu...

Answered by Lauren S. • Chemistry tutor

18248 Views

What is the position of chemical equilibrium and how can it change? (A-Level/high GCSE)

A dynamic chemical equilibrium refers to a reversible chemical reaction, where the forward and reverse reactions are happening at the same rate. This results in the concentrations of reactant and product ...

Answered by James C. • Chemistry tutor

28467 Views