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Why do the atomic radii of the elements decrease across a period?

Moving across a period the number of protons and neutrons that make up the nucleus of the element increases. The increase in the number of positively charged protons results in an increased nuclear charge...

Answered by Harry K. • Chemistry tutor

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How can pressure affect the equilibrium shift of a reversible gaseous reaction?

Le Chatelier's Principle states the if a change is applied to a system in equilibrium, then the position of equilibrium will move to counteract that change. So, if the pressure was increased for a reactio...

Answered by Tejal W. • Chemistry tutor

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In a titration, 45.0 cm^(3) of 0.100 mol dm^(-3) sodium hydroxide solution is exactly neutralised by 40.0 cm^(3) of a dilute hydrochloric acid solution. Calculate the concentration of the hydrochloric acid solution in mol dm^(-3).

First of all, summarise everything that you know in a table or in brief notes:NaOH, 45 cm^(3), 0.1 mol dm^(-3)HCl, 40 cm^(3)The first thing that you need to do is to find the number of moles of NaOH. This...

Answered by Lauren J. • Chemistry tutor

4622 Views

What does the strength of lattice enthalpy of formation depend on?

So, lattice enthalpy of formation is defined as the 'standard enthalpy change when one mole of an ionic crystal lattice is formed from its constituent ions in gase...

Answered by Zaynab A. • Chemistry tutor

2410 Views

How are trends in ionisation energy explained?

Horizontal trend: First ionisation energies increase going to the right in a period. This is due to an increase in the atomic mass (and number of protons) and hence in the electrostatic attraction between...

Answered by Miruna C. • Chemistry tutor

1410 Views