Fil up
1. ___________ are sour. in taste
2. lemon contains _______ acid , where as milk has _________ acid
3. ________ is used as an ant acid
4. the reaction between vinegar and baking soda is a _________ reaction
5. when a bee sting it injects on ________ into the skin
Answers
Answer:
1 lemon
2citric , lactic
3bicarbonate
4devomposive
5letrick
Explanation:
make me brain list
Answer:
1. What colour do the following indicators turn when added to a base or alkali (such as sodium hydroxide)?
(a) Methyl orange (b) litmus (c) red cabbage extract
Solutions:
(a) When methyl orange is added to a base it turns colour into yellow
(b) Litmus paper changes into blue when dipped in base solution. It changes colour from red to blue as the solution is alkali
(c) Red cabbage extract turns into green colour when added to a base
2. What colours do the following indicators turn when added to an acid (such as hydrochloric acid)
(a) Litmus (b) methyl orange
Solutions:
(a) Litmus paper is an indicator used to identify the whether the solution is acidic or basic. Here when this is dipped in acidic solution like hydrochloric acid it turns blue colour to red.
(b) Methyl orange is also an indicator shows colour change in different solutions. In acid solutions it changes its colour to red.
3. Name an indicator which is red in acid solution but turns blue in basic solution.
Solutions:
Litmus is used as an indicator to identify the solution is acidic or basic by changing its colour from solution to solution. In acidic solution the litmus colour changes from blue to red and in alkali solutions the colour changes from red to blue.
4. Name an indicator which is pink in alkaline solution but turns colourless in acidic solution.
Solutions:
Phenolphthalein is used as an indicator in acid-base titrations and it turns colourless in acidic solutions and turns into pink in basic solutions.
5. When a solution is added to a cloth strip treated with onion extract, then the smell of onion cannot be detected. State whether the given solution contains an acid or base.
Solutions:
The given solution contains base because onion extract loses its smell when added to a base, but its smell does not change when added to acid.
6. When a solution is added to vanilla extract, then the characteristic smell of vanilla cannot be detected. State whether the given solution is an acid or a base.
Solutions:
The given solution will be base because when a basic solution is added to vanilla it completely destroys the characteristic smell of vanilla and when in acidic solution it does not change
7. How will you test for the gas which is liberated when hydrochloric acid reacts with an active metal?
Solution:
When hydrochloric acid reacts with active metal hydrogen gas will be evolved at the surface of the metal in the form of bubbles and thus formed gas is passed through soap and bring candle near the bubble formed. If the gas burns with a pop sound then it can be concluded that it is hydrogen.