Tiêu đề EDX Topic 10.2 chemical tests .pdf ✅

Topic 11 2 Tests for Gases Gas Test Results Carbon Dioxide Lime water Turns milky Sulfur Dioxide Acidified Potassium Manganate (VII) changes colour from purple to colourless Hydrogen Lighted splint Burns with a pop sound Oxygen Glowing splint Relights Chlorine Damp litmus paper Bleaches / turns white. Ammonia Damp red litmus paper Turns blue.

4 Physical Test for Water: A physical test to see if a sample of water is pure to check its boiling point A sample of the liquid is placed in a suitable container such as a boiling tube and gently heated Using a thermometer, you can check if the boiling point is exactly 100°C Any impurities present will usually tend to raise the boiling point and depress the melting point of pure substance Flame Tests The flame test is used to identify the positive metal ion (cations) by the colour of the flame they produce Ions from different metals produce different colours To carry out a flame test: Dip the loop of an unreactive metal wire such as nichrome or platinum in concentrated hydrochloric acid then rinse with distilled water to clean it & remove traces of any ions on it Hold it in the blue flame of a Bunsen burner until there is no colour change Dip the loop into the solid sample / solution and place it in the edge of the blue Bunsen flame It is important to place the wire into acid first to prevent contamination Not doing this might result in two or more ions being present on the wire meaning the colours will mix One colour could mask another colour and you will not be able to identify the ion The colour of the flame is observed and used to identify the metal ion present Topic 11