Calculating the rate equation from initial rates

Watch the following clip to help with understanding how to find the rate equation form experimental data.

Reactivity of Group 7 elements

These elements are found in the same group as they have the same number of electrons in their outer shells. They have similar properties as they all need one electron to get a full outer shell. Trends: Atomic Size – Increases down the group, as the atoms have more shells Density – Increases down the group, as the atomic mass increases (more protons and neutrons). Reactivity – Decreases down the group, as it is harder for the nucleus to attract an outer electron, as the outer shell is further from the nucleus and the inner shells shield the attractive force of the nucleus.

It is important to know the reactivity of the halogens with iron wool and with halide salt solutions in displacement reactions:

Reactivity of Group 1 metals

These elements are found in the same group as they have the same number of electrons in their outer shells. They have similar properties as they all need to lose one electron to get a full outer shell. Trends: Atomic Size – Increases down the group, as the atoms have more shells Density – Increases down the group, as the atomic mass increases (more protons and neutrons). Reactivity – Increases down the group, as it is harder for the nucleus to attract the outer electron, as the outer shell is further from the nucleus and the inner shells shield the attractive force of the nucleus. So the outer electron is more easily lost

The Royal Society of Chemistry video below shows the reactivities of some of the Group 1 metals:

Global Warming

This is a YouTube video showing the Scientific Eye programme on Global Warming, some useful ideas and explanations!

Limestone

Limestone is a sedimentary rock found in the earth.  It is formed from the shells of dead sea creatures which become crushed and buried at the bottom of the sea, when these creatures die.

Limestone is made up of the chemical calcium carbonate, CaCO₃.  It is a metal carbonate. The following YouTube video is from the Scientific Eye series and explains the importance of limestone and the issues related to it.  You might be expected to discuss the social, economic and environmental of extracting and using limestone.

Limestone can undergo reactions as part of the 'Limestone cycle'.  The first step is a thermal decomposition, this is where a substance is broken down into smaller compounds using heat. The ease with which they decompose varies within a group. The higher up the reactivity series a metal is, the more stable its carbonate will be, so the least reactive metals have the carbonates that decompose most readily. Looking at group 2 magnesium carbonate decomposes relatively easily, calcium carbonate requires significant heating to decompose. As you go further down the group the metal carbonates become more stable and less easily decomposed by heat.

Calculating Reacting Masses 2

The earlier 'Calculating Reacting Masses' blog, talked about how you could use factors between the molecular masses of substances and their actual masses in order to find the mass of an unknown in a chemical reaction.  A more useful way of doing this is to look at the moles of substances in reactions, the following slideshow explains this, pause and repeat to get a better understanding. 

Look at the original 'Reacting Masses' blog post. Does the moles method give the same result as the worked example?

WJEC Textbook Resource Materials

The WJEC have a publishing partnership with Hodder (GCSE) and Illuminate publishing (A Level) to provide textbooks and revision materials.  Click on the links below to access the specific material.

WJEC GCSE Chemistry
My Revision Notes: WJEC GCSE Chemistry

WJEC Chemistry for AS: Student Book
WJEC Chemistry for AS: Study and Revision Guide

WJEC Chemistry for A2: Student Book
WJEC Chemistry for A2: Study and Revision Guide