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Chemistry
A Level

Draw the structure, name the shape and show bond angles of the molecules XeF4 and SbF4-. In your answer explain why each structure is different, despite both having a central atom, surrounded by 4 fluorine atoms.

Xe is in group 8, the noble gases. Therefore it has 8 electrons in its outer shell. Fluorine atoms have 7 electrons, yet one is an unpaired electron, so this is the electron in fluorine that gets involved...

Answered by George J. Chemistry tutor
20872 Views

By considering the mechanism of the two step reaction of butanone and NaBH4 followed by dilute acid, explain why the product has no effect on plane polarised light.

CH3-CO-CH2-CH3 + 2[H] --> CH3-CHOH-CH2-CH3 NaBH4 is a reducing agent that effectively produces an H- ion to act a...

Answered by Alex J. Chemistry tutor
13882 Views

State and explain the general trend in the first ionisation energy across a period.

First, let's check we understand the concept of the first ionisation energy. The term is defined as 'the energy required to remove a mole of electrons from a mole of gaseous atoms'. That is, for ea...

Answered by Ben M. Chemistry tutor
3796 Views

Giving the electronic configurations for each element, predict the trend in 1st ionisation energies going across period 2 from Lithium to Neon.

First start by giving the definition of first ionisation energy - the energy required to remove one mole of electrons from one mole of gaseous atoms to produce one mole of gaseous ions each with a +1 char...

Answered by Alexandra B. Chemistry tutor
2948 Views

i)Explain why first ionisation energy shows a general tendency to increase across a period? ii)Using period 3 as an example, which elements show irregularities in this trend and why?

i)As you move across a period the number of protons in the nucleus, and so the overall nuclear charge, increases. All extra electrons are roughly the same energy and distance from the nucleus. This means ...

Answered by David M. Chemistry tutor
6038 Views

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