Advertisements
Advertisements
प्रश्न
Choose the correct alternative and rewrite the following sentence.
Which of the following is not required to find the pH of a given solution?
विकल्प
pH paper
Litmus paper
Standard pH value chart
- Universal indicator
उत्तर
Litmus paper
APPEARS IN
संबंधित प्रश्न
Translate the following statement into chemical equation and then balance it.
Hydrogen sulphide gas burns in the air to give water and sulphur dioxide.
How will you indicate Endothermic reaction in a chemical equation?
Rewrite the following information in the form of a balanced chemical equation:
Magnesium burns in carbon dioxide to form magnesium oxide and carbon.
Substitute formulae for names and balance the following equation:
Calcium carbonate reacts with hydrochloric acid to produce calcium chloride, water and carbon dioxide gas.
State the various characteristics of chemical reactions.
Is Decomposition of calcium carbonate an endothermic reaction or an exothermic reaction?
When the solution of substance X is added to a solution of potassium iodide, then a yellow solid separates out from the solution.
(a) What do you think substance X is likely to be?
(b) Name the substance which the yellow solid consists of.
(c) Which characteristic of chemical reaction is illustrated by this example?
(d) Write a balanced chemical equation for the reaction which takes place. Mention the physical states of all the reactant and products involved in the chemical equation.
When metal X is treated with a dilute acid Y, then a gas Z is evolved which burns readily by making a little explosion.
(a) Name any two metals which can behave like metal X.
(b) Name any two acids which can behave like acid Y.
(c) Name the gas Z.
(d) Is the gas Z lighter than or heavier than air?
(e) Is the reaction between metal X and dilute acid Y, exothermic or endothermic?
(f) By taking a specific example of metal X and dilute acid Y, write a balanced chemical equation for the reaction which takes place. Also indicate physical states of all the reactants and products.
A metal X forms a salt XSO4. The salt XSO4 forms a clear solution in water which reacts with sodium hydroxide solution to form a blue precipitate Y. Metal X is used in making electric wire and alloys like brass.
(a) What do you think metal X could be?
(b) Write the name, formula and colour of salt XSO4.
(c) What is the blue precipitate Y?
(d) Write a chemical equation of the reaction which takes place when salt XSO4 reacts with sodium hydroxide solution. Give the state symbols of all the reactants and products which occur in the above equation.
The metal M reacts vigorously with water to form a solution S and a gas G. The solution S turns red litmus to blue whereas gas G, which is lighter than air, burns with a pop sound. Metal M has a low melting point and it is used as a coolant in nuclear reactors.
(a) What is metal M?
(b) What is solution S? Is it acidic or alkaline?
(c) What is gas G?
(d) Write a balanced chemical equation for the reaction which takes place when metal M reacts with water.
(e) Is this reaction exothermic or endothermic?
Balance the following chemical equation:
What happens when silver nitrate solution is added to sodium chloride solution?
Write the equation for the reaction which takes place.
A white precipitate can be obtained by adding dilute sulphuric acid to:
(a) CuSO4 solution
(b) Nacl solution
(c) BaCl2 solution
(d) Na2SO4 solution
Write word equation for the following skeletal equation:
\[\ce{CO + O2 -> CO2}\]
Write your observation for the following chemical reaction and name the product formed:
When sugar is heated.
Write your observation for the following chemical reaction and name the product formed :
When dilute acetic acid is poured on baking soda.
Balance the following equation. Also name the product formed.
`"H"_2 +"CI"_2 → "HCI"`
Complete the following equation:
CH4 + O2 —>
Balance the equation stepwise.
SO2(g) + H2S(aq) → S(s) + H2O(l)
State the information conveyed by the following equation:
Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2 ↑
Balance the following equation:
Fe2O3 + CO → Fe + CO2
Balance the following equation:
PbO + NH3 → Pb + H2O + N2
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.
copper + nitric acid → copper nitrate + nitric oxide + water
Write the balanced chemical equation of the following reaction.
ammonia + oxygen → nitric oxide + water
Answer the following question.
What is observed when 2 mL of dilute hydrochloric acid is added to 1 g of sodium carbonate taken in a clean and dry test tube? Write a chemical equation for the reaction involved.
Write word equation for the following molecular equation:
CuCo3 → CuO + CO2 [g]
Word equation:
State the characteristics or indications occurring in the above reaction.
In certain reaction a change of state is observed i.e. solid to liquid, liquid to gas etc. – State the change of state of the products – to give the respective reactant.
\[\ce{C +2S -> CS2}\]
Give word equation for the following chemical reaction and give the names of the product formed.
Zn + 2HC1→ ZnCl2 + H2
Balance the following simple equation:
\[\ce{N2 + H2 <=> NH3}\]
Balance the following simple equation:
Fe2O3 + CO → Fe + CO2
In the chemical equation the _______ are written on the left-hand side.
What are reactants? Explain with the help of example.
Balance the given chemical reaction as per the instructions below.
\[\ce{NaOH + H2SO4 -> Na2SO4 + H2O}\]
Write the number of atoms of various elements in the reactants and products.
Write the skeleton equation for the following word equation and then balance them.
- Carbon + Oxygen → Carbon dioxide.
- Phosphorus + Chlorine → Phosphorus pentachloride.
- Sulphur + Oxygen → Sulphur dioxide.
- Magnesium + hydrogen → Magnesium + Hydrogen chloride chloride.
A dilute ferrous sulphate solution is gradually added to the beaker containing acidified permanganate solution. The light purple colour of the solution fades and finally disappears. Which of the following is the correct explanation for the observation?
Give the characteristic tests for the following gases :
- CO2
- SO2
- O2
- H2
Complete the following blank in the equation as indicated.
\[\ce{CaH2_{(s)} + 2H2O_{( aq)}-> Ca(OH)2_{(s)} + 2H2_{(g)}}\]
Grams: 42 g + ______ `→` ______ + ______
Why should a magnesium ribbon be cleaned before burning in air?
