Search our library of Chemistry questions

Top answers

Chemistry

All levels

Magnesium oxide contains magnesium ions (Mg2+) and oxide ions (O2–). Describe what happens when magnesium atoms react with oxygen atoms to produce magnesium oxide.

magnesium ions loses two electrons becoming Mgoxygen gains two electron becoming OThis now means both the atoms have a full shell

Answered by Rabia D. • Chemistry tutor

7681 Views

In the equation 2Na + 2H2O ---> 2NaOH + H2, is Na oxidised or reduced and why?

Write out the equation and explain the OIL RIG acronym.2Na + 2H₂O ---> 2NaOH + H₂Write the changes in oxidation state of Na. Na goes from an oxidation state of 0 to an oxidation ...

Answered by • Chemistry tutor

6906 Views

Explain why water molecules form on average two hydrogen bonds per molecule, whereas ammonia molecules (NH3) form only one.

A hydrogen bond requires both a lone pair of electrons on a O, N or F atom and a hydrogen atom. In water there are two lone pairs and two hydrogen atoms, allowing the formation of two hydrogen bonds. In a...

Answered by • Chemistry tutor

9516 Views

Why does grinding a solid reactant down into smaller lumps increase the rate of a reaction? (2/3 marks)

As grinding down the solid increases the exposure of particles on the surface, this increases the frequency of reactant particle collisions which then increases the rate of reaction.

Answered by Isabelle H. • Chemistry tutor

3539 Views

The equation for the reaction of carbon and nickel dioxide is: NiO + C ----> CO + Ni Calculate the percentage atom economy of this reaction to produce nickel to 3 significant figures.

Using a periodic table, you can find that: Molecular mass of carbon: 12Molecular mass of nickel: 59Formula mass of nickel oxide: 75 (=59+16)
Mass of all the reactants = 12+75=87Mass of the product we...

Answered by Emma N. • Chemistry tutor

4633 Views