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Chemistry

A Level

Calculate the mass, in grams, of CH3CH2NH2 produced from 32.9 g of CH3CH2I reacting with an excess of NH3 assuming a 70.0% yield.

To tackle any question like this, you should first write out the reaction formula (I would do this on the whiteboard). You can see from this that the ratio between the reactant and product is 1:1. You can...

Answered by Rob B. • Chemistry tutor

3745 Views

Calculate the pH of the following solutions: 0.002 mol/dm^-3 KOH

pH by definition is given as -log₁₀(c_H+) or log₁₀(1/c_H+), where c_H+ is the concentration of the H+ ions in the solution.Similarly, pOH= -log₁₀

Answered by Csaba B. • Chemistry tutor

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Why do transition metals form coloured compounds?

Transition elements have 3d orbitals with the same energy level however when molecules/ligands form dative covalent bonds with a metal ion, the electron repulsion causes the 3d orbitals to split into lowe...

Answered by Chiamaka C. • Chemistry tutor

30120 Views

Identify which 2 of the following processes involve an exothermic change: melting, boiling, freezing, deposition and sublimation

An exothermic reaction involves an output of heat, so heat is lost overall. This would mean that boiling and melting are definitely not exothermic as they involving putting in heat. Free...

Answered by Ellen S. • Chemistry tutor

5463 Views

What is the easiest way to calculate E cell values?

This is a calculation which students often find tricky. One fail-safe method for doing this calculation is considering E cell = E (reduced) - E(Oxidised). A more positive electrode potential means that a ...

Answered by Rajinder D. • Chemistry tutor

39197 Views