Advertisements
Advertisements
Question
State one characteristic of the chemical reaction which takes place when lemon juice is added gradually to potassium permanganate solution.
Advertisements
Solution
Lemon juice (contains citric acid) changes the purple colour of potassium permanganate solution to a colourless solution. Hence, this reaction is characterised by change in colour.
APPEARS IN
RELATED QUESTIONS
2 mL of sodium hydroxide solution is added to a few pieces of granulated zinc metal taken in a test tube. When the contents are warmed, a gas evolves which is bubbled through a soap solution before testing. Write the equation of the chemical reaction involved and the test to detect the gas. Name the gas which will be evolved when the same metal reacts with dilute solution of a strong acid.
Write complete balanced equation for the following reaction:
Calcium (solid) + water (liquid) 
Calcium Hydroxide (solution) + Hydrogen (gas)
Balance the given equation:
AI(OH)3 
AI2O3 +H2O
When hydrogen is passed over copper oxide, copper and steam are formed. Write a balanced equation for this reaction and state which of the chemicals are products.
State the various characteristics of chemical reactions.
State one characteristic of the chemical reaction which takes place when dilute hydrochloric acid is added to sodium carbonate.
Balance the following chemical equation:
Balance the equation stepwise.
SO2(g) + H2S(aq) → S(s) + H2O(l)
Write the answer to the following.
Explain the similarity and difference in two events, namely adding NaOH to water and adding CaO to water.
Write the balanced chemical equations of the following reactions.
chlorine + sulphur dioxide + water → sulphuric acid + hydrogen chloride
Write the balanced chemical equation of the following reaction.
zinc sulphide + oxygen → zinc oxide + sulphur dioxide
Complete the following blank in the equation as indicated.
\[\ce{CaH2_{(s)} + 2H2O_{( aq)}-> Ca(OH)2_{(s)} + 2H2_{(g)}}\]
Moles: 1 mole + ______ `→` ______ + ______
\[\ce{MnO2 + 4HCl -> MnCl2 + 2H2O + Cl2}\]
0.02 moles of pure MnO2 is heated strongly with conc. HCl. Calculate mass of MnO2 used.
Match column A with column B.
| Column A | Column B |
| (a) Blue salt changes to white and then black | (i) Ammonium dichromate |
| (b) Orange coloured compound changes to green. | (ii) Iodine |
| (c) Red compound changes to brown and then yellow. | (iii) Zinc Nitrate |
| (d) White to yellow when hot and white when cold. | (iv) Copper sulphate |
| (e) Violet solid changes to violet vapours. | (v) Red Lead |
A chemical reaction is generally accompanied by certain external indications or characteristics. These include – change of – (a) colour (b) state (c) smell (d) evolution of gas (e) formation of precipitate (f) evolution or absorption of heat. With reference to change of colour – state the change in colour seen when the following are heated – mercury [II] oxide.
What is meant by ‘reactants’ and ‘products’ in a chemical equation?
Balance the following simple equation:
Al + O2 → Al2O3
Balance the following simple equation:
CO2 + C → CO
Balance the following simple equation:
KBr + Cl2 → KCl + Br2
Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.
3CuO + NH3 → 3Cu + 3H2O + N2
