Search Results

Reaction Mechanism: reactions rarely proceed in a single step as written. They take place in a series of smaller steps called a reaction mechanism. Grade 10 SABIS

< Back This is a Title 03 This is placeholder text. To change this content, double-click on the element and click Change Content. This is placeholder text. To change this content, double-click on the element and click Change Content. Want to view and manage all your collections? Click on the Content Manager button in the Add panel on the left. Here, you can make changes to your content, add new fields, create dynamic pages and more. You can create as many collections as you need. Your collection is already set up for you with fields and content. Add your own, or import content from a CSV file. Add fields for any type of content you want to display, such as rich text, images, videos and more. You can also collect and store information from your site visitors using input elements like custom forms and fields. Be sure to click Sync after making changes in a collection, so visitors can see your newest content on your live site. Preview your site to check that all your elements are displaying content from the right collection fields. Previous Next

< Back A level Equilibria Previous Next

5. Any reaction or process that consumes heat energy. Endothermic Grade 10 SABIS SABIS

< Back Sabis Grade 10 Chemistry Previous Next

In general, reactions in which bonds are broken and formed tend to be slow. Grade 10 SABIS

< Back Hydrogen gas Part 1 Physical properties of hydrogen 1. Colorless odorless gas 2. Neutral to litmus 3. Less dense than air (so collected by upward delivery) 4. Insoluble in water (can be collected over water) 5. Highly flammable Reaction of Hydrogen Gas with Air Reacts with air violently (oxygen) when in contact with a flame. So it makes a squeaky pop with a lit splint 2H2(g) + O2 --> 2H2O Isotopes of Hydrogen Isotopes are atoms of the same element which have the same number of protons (atomic number) but different number of neutrons (mass number). Preparation of Hydrogen gas First : in Laboratory 1-Preparing hydrogen from water or steam Addition of Very reactive metals (example potassium , Sodium , Lithium , Calcium) + liquid water gives hydrogen gas and metal hydroxide. or Addition of metals to steam to produce metal oxide and hydrogen gas 2- Preparing Hydrogen from acids Addition of moderately reactive metals like magnesium aluminum zinc or iron to dilute hydrochloric acid or sulfuric acid Note that less reactive metals can not be used to prepare the hydrogen with dilute acids generally metals which are less reactive than hydrogen can not be used Second : Industrially 1-Using hydrocarbons example by heating a hydrocarbon like methane with steam using a catalyst like nickel , the product is Carbon monoxide and hydrogen gas The carbon monoxide produced can be reheated with more steam using an iron oxide catalyst to produce Carbon dioxide and hydrogen gas 2-Using coke Coke is a fuel made of coal The coke is reacted with steam at high temperature (around 1000) degrees celsius to produce carbon monoxide gas and hydrogen gas 3-Using Electrolysis Electrolysis is the breakdown of a substance using electric current the water is broken down by electrolysis into hydrogen and oxygen Or the NaCl solution (brine) is broken down into chlorine and Hydrogen gases Previous Next

Coefficients Grade 10 SABIS SABIS The numbers placed before the reactants and products in a chemical equation, indicating how many molecules or atoms are involved.

Potassium reacts with hydrogen, oxygen, fluorine and chlorine to form white solids. Grade 10 SABIS

Convenient Reaction Ratio Grade 10 SABIS SABIS The ratio in which reactants combine or react to form products. It is often based on the coefficients in the balanced chemical equation and is used to simplify stoichiometric calculations.

Generally, reactions with low activation energy tend to be fast Grade 10 SABIS

Melting Point/Freezing Point The specific temperature at which a substance changes from a solid to a liquid state (melting) or from a liquid to a solid state (freezing).