Top answers

Elemental analysis of a carbohydrate X showed the sample contained 48.7 % carbon and 8.1 % hydrogen by mass. Find the empirical formula of X.

These sorts of questions can look difficult, but if you learn the steps needed to solve them then they are all very similar. Step 1: Since we are told that X is a carbohydrate, we know that the only other co...
JB
Answered by Jack B. • Chemistry tutor
2165 Views

Explain the trend in ionisation energies for the group one metals?

The first ionisation energy of an element is the minimum energy required to remove a single electron from one mole of an element in its gaseous state. As you go down the group the first electron becomes easi...
DC
Answered by Dan C. • Chemistry tutor
2567 Views

X, a gas, has a mass of 0.270g and is present in a gas syringe with a volume of 105.0cm^3 at 97C and 100kPa. Calculate the Mr of X. (5 marks)

This is a classic A-level question which uses the formula:PV=nRT First, this equation (which needs to be learnt, it is not given in the exam papers) must be rearranged to:n=PV/RTWhat all these letters in the...
JB
Answered by Jack B. • Chemistry tutor
3335 Views

What is the difference between E-Z isomers and optical isomers?

E-Z isomers (aka geometric or cis-trans isomers) and optical isomers are both examples of stereoisomers, two or more compounds with the same structural formula but with bonds that are arranged differently in...
JM
Answered by Jessie M. • Chemistry tutor
13066 Views

Why does ionization energy increase across a period?

First of all, let's define ionization energy. Ionization energy is the energy needed to remove 1 electron from each atom in 1 mole of gaseous atoms. The higher this energy is, the harder it is to remove the ...
AF
Answered by Amelia F. • Chemistry tutor
32506 Views