Plan An Investigation into how the rates of reactions are affected by the concentration of hydrochloric acid

Authors Avatar

An Investigation into how the rates of reactions are affected by the concentration of hydrochloric acid

Plan

The investigation I am going to do is to find out how the concentration of hydrochloric acid will affect the rate of a reaction with Soda Mint Tablets. The input variable I am going to change each time will be the concentration of the acid. The concentrations I am going to use for this experiment are; 1molar, 1.5molar, 2molar, 2.5molar and 3molar.

A rate of reaction is how fast or slow a reaction happens between two or more chemicals to chemically join together .We can measure rates of reactions in many different ways for example: the volume of gas there is e.g. carbon dioxide and the concentration of the substance/mixture.

There are five factors that will affect the rate of reaction there are as follows:

  • Temperature: Temperature will effect the rate of the reaction because as the acid heats up, the acid particles (or ions) will heat up to making them move around the container much faster increasing the chance of a collision with other acid particles, as the particles collide with each other the rate of the reaction is increased. Trying to control this factor in my experiments will be quite difficult but I will try to do all the experiments in an equally spaced time so that the equipment doesn’t get warm from all the reactions occurring one after another.
  • Concentration: The concentration of the acid will effect the reaction a lot because the higher the concentration the faster the reaction will happen e.g. a 1molar acid will react slower than a 3molar acid, this occurs because the higher the concentration is the more acid particles it contains, having more particles means that more collisions are possible and so the reaction happens faster. This factor is easily controlled by washing the conical flak out after each time it has been used to make sure that there is none of the previous acid there then dry it so that the water does not dilute the next acid.
  • Surface area: The surface area  affects the rate of reaction because the more surface area it has the faster the reaction can occur e.g. if there was a solid piece of limestone and some powdered limestone in acid  the powdered limestone would react faster because there is more areas for the acid to attack (more surface area). This factor is quite easily controlled in by weighing the limestone chips we used in the preliminary experiment but this way is not very accurate because the chips are all different weights so in the final investigation we are going to use Soda Mint tablets because they are all the same weight and they react faster. (see evaluation)
  • Catalysts: Catalysts affect the rate of reaction because they speed up a reaction without using itself up, it does this by providing a different route for the reaction with the less activation energy. Another way in which a catalyst can speed up a reaction is  through  absorption this happens because all the particles in the solution are close together they stick to the catalyst and increase a chance of a collision with other particles. These factors affect the rate of reaction but the catalyst does not chemically change in any way (it stays the same). This factor will not be a problem in my experiments because I am not going to use any catalysts in the investigation.
  • Gas Pressure: Gas pressure affects the rate of reaction because when you increase the pressure the reaction occur faster and when you reduce the pressure the reaction occurs slower. This happen because when you are increasing the pressure all the particles in the substance are being squashed together making less room for them to move around and increasing a chance of a collision with other particles in the substance. Because there is gas building up in the conical flask because of the reaction, the gas is going up the delivery tube and collecting in the gas syringe recording the amount of Carbon Dioxide (CO2) so this factor does not really need to be controlled.
Join now!

Preliminary

I am going to carry out a preliminary (trail) experiment. In my trail experiment I am going to use limestone chips instead of the Soda Mint tablets, the acids I am going to use are 1molar, 1.5molar, 2molar, 2.5molar and 3molar.

But in these trail experiments I am only going to do the experiments once and not going to repeat them because there is no need to if they are trail experiments.

The equation to show the reaction is as follows:

Calcium carbonate + hydrochloric acid  calcium chloride + water + carbon dioxide or Ca Co3 + ...

This is a preview of the whole essay