Thank you for choosing Thames & Kosmos and for your interest in our Chemistry kits.
There are some additional chemicals that cannot be included in the advanced CHEM kits due to safety restrictions and their limited shelf-lives. I have put together the following list of the chemicals you will need below.
Additional Chemicals Needed for CHEM C3000 (due to legal restrictions or limited shelf life)
• Approximately 10 ml of silver nitrate solution, (1% Solution)
• Approximately 100 ml of sodium hydroxide, 1mol/L (4% Solution)
• Approximately 100 ml of hydrochloric acid, 2mol/L (7% Solution)
• Approximately 50 ml of ammonia solution 2mol/L (3.4% Solution)
70% Ethyl Alcohol (a form of Denatured Alcohol), and Hydrogen Peroxide are also required for certain experiments but cannot be included in the kit due to certain restrictions. You should be able to find these two items in the first aid aisle of most pharmacies.
Ammonia should be obtainable from most supermarkets in the cleaning aisle. Generally speaking, household cleaning ammonia will typically range in concentration from 5% to 10%. The product labeling should indicate the concentration.
The proper dilution of ammonia solution is approximately 3.4%, and this can be attained by adding common household ammonia to the appropriate amount of water (see below). The amount of water that you will need depends on the volume required for a given experiment and the percentage of the solution you are starting with.
**Important!** When diluting chemicals, always add the chemical to the water, not the other way around. In general, if you pour water on top of certain chemicals, a reaction can occur quickly causing the solution to splash back up at you. However, if you carefully add the chemical to the water, you can avoid this.
You may find it easier to create a larger volume of properly diluted solution and store it for use as needed.
As an example, let’s assume that you are starting with household ammonia which is at an 8% solution. If you wanted to make a 4% solution from that, you would combine equal parts water and ammonia. By adding 25ml of ammonia (@ 8% by volume) to 25ml of water you would thus create a 4% solution.
Therefore, to reach a 3.4% solution, you would need to dilute the ammonia by a little more than half.
Once again, let’s assume that you are starting with an 8% ammonia solution. If 50 ml of ammonia solution is required, you would need to add 21ml of ammonia to 28ml of water. (3.4%/8% = .425 -> .425 x 50ml = 21.25ml, or approx. 21ml).
If you have any additional questions about this or any of our other kits, please do not hesitate in sending an email to firstname.lastname@example.org.
Thank you again for choosing Thames & Kosmos and for your interest in our CHEM kits. We hope you and your family will continue to enjoy our products for many years to come.
The Thames & Kosmos Technical Support Team