Advertisements
Advertisements
प्रश्न
With the help of an appropriate example, justify that some of the chemical reactions are determined by the evolution of a gas.
Give a chemical equation for the reaction involved in the above case.
Give one example of a chemical reaction characterised by the evolution of a gas.
Advertisements
उत्तर
When zinc granules react with dilute sulphuric acid in a flask, hydrogen gas evolves, and zinc sulphate solution is formed.
\[\ce{Zn_{(s)} + H2SO4_{(aq)} -> ZnSO4_{(aq)} + H2_{(g)}}\]
Notes
Students should refer to the answer according to their questions.
APPEARS IN
संबंधित प्रश्न
Why should a magnesium ribbon be cleaned before it is burnt in the air?
Balance the following equation:
\[\ce{Na + O2 -> Na2O}\]
What is a chemical equation? Explain with the help of an example.
When water is added gradually to a white solid X, a hissing sound is heard and a lot of heat is produced forming a product Y. A suspension of Y in water is applied to the walls of a house during white washing. A clear solution of Y is also used for testing carbon dioxide gas in the laboratory.
- What could be solid X? Write its chemical formula.
- What could be product Y? Write its chemical formula.
- What is the common name of the solution of Y which is used for testing carbon dioxide gas?
- Write chemical equation of the reaction which takes place on adding water to solid X.
- Which characteristic of chemical reactions is illustrated by this example?
Write your observation for the following chemical reaction and name the product formed :
When an aqueous solution of sodium chloride is mixed with an aqueous solution of silver nitrate.
Write your observation for the following chemical reaction and name the product formed :
When ammonium chloride is heated with sodium hydroxide.
In electrolysis of water, why is the volume of gas collected over one electrode double that of gas collected over the other electrode?
Balance the equation stepwise.
Ag(s) + HCl(aq) → AgCl ↓+ H2 ↑
Balance the following equation:
Ca + N2 → Ca3N2
What information do the following chemical equations convey? Mg + 2HCl → MgCl2+ H2
Write the balanced chemical equation of the following reaction.
barium chloride + sulphuric acid → barium sulphate + hydrochloric acid
Write the balanced chemical equation of the following reaction.
zinc sulphide + oxygen → zinc oxide + sulphur dioxide
A student mixes sodium sulphate powder in barium chloride powder. What change would the student observe on mixing the two powders? Justify your answer and explain how he can obtain the desired change.
Give word equation for the following chemical reaction and give the names of the product formed.
Zn + S → ZnS
Give word equation for the following chemical reaction and give the names of the product formed.
ZnCO3 → ZnO + CO2
Give an example of a chemical equation in which two reactants form:
one product
Balance the following simple equation:
KHCO3 → K2CO3 + H2O + CO2
What are products? Explain with the help of example.
Three beakers labelled as A, B and C each containing 25 mL of water were taken. A small amount of NaOH, anhydrous CuSO4 and NaCl were added to the beakers A, B and C respectively. It was observed that there was an increase in the temperature of the solutions contained in beakers A and B, whereas in case of beaker C, the temperature of the solution falls. Which one of the following statement(s) is(are) correct?
- In beakers A and B, exothermic process has occurred.
- In beakers A and B, endothermic process has occurred.
- In beaker C exothermic process has occurred.
- In beaker C endothermic process has occurred.
What is a reactant in a chemical equation?
