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Chemical Reactions and Equations

Why do we store silver chloride in dark coloured bottles?

06/11/2024

Science

10th

Chemical Reactions and Equations

Write a balanced chemical equation for each of the following reactions and also classify them.
(a) Lead acetate solution is treated with dilute hydrochloric acid to form lead chloride and acetic acid solution.
(b) A piece of sodium metal is added to absolute ethanol to form sodium ethoxide and hydrogen gas.
(c) Iron (III) oxide on heating with carbon monoxide gas reacts to form solid iron and liberates carbon dioxide gas.
(d) Hydrogen sulphide gas re

06/11/2024

Science

10th

Chemical Reactions and Equations

A substance X, which is an oxide of a group 2 element, is used
intensively in the cement industry. This element is present in bones
also. On treatment with water it forms a solution which turns red
litmus blue. Identify X and also write the chemical reactions involved.

06/11/2024

Science

10th

Chemical Reactions and Equations

During the reaction of some metals with dilute hydrochloric acid, following observations were made.
(a) Silver metal does not show any change
(b) The temperature of the reaction mixture rises when aluminium (Al) is added.
(c) The reaction of sodium metal is found to be highly explosive
(d) Some bubbles of a gas are seen when lead (Pb) is reacted with the acid.
Explain these observations giving suitable reasons.

06/11/2024

Science

10th

Chemical Reactions and Equations

Which among the following are physical or chemical changes?
(a) Evaporation of petrol
(b) Burning of Liquefied Petroleum Gas (LPG)
(c) Heating of an iron rod to red hot.
(d) Curdling of milk
(e) Sublimation of solid ammonium chloride

06/11/2024

Science

10th

Chemical Reactions and Equations

Grapes hanging on the plant do not ferment but after being plucked from the plant can be fermented. Under what conditions do these grapes ferment? Is it a chemical or a physical change?

06/11/2024

Science

10th

Chemical Reactions and Equations

Why do fire flies glow at night?

06/11/2024

Science

10th

Chemical Reactions and Equations

Ferrous sulphate decomposes with the evolution of a gas having a characteristic odour of burning sulphur. Write the chemical reaction involved and identify the type of reaction.

06/11/2024

Science

10th

Chemical Reactions and Equations

A solution of potassium chloride when mixed with silver nitrate
solution, an insoluble white substance is formed. Write the chemical
reaction involved and also mention the type of the chemical reaction?

06/11/2024

Science

10th

Chemical Reactions and Equations

Write the balanced chemical equations for the following reactions
(a) Sodium carbonate on reaction with hydrochloric acid in equal molar concentrations gives sodium chloride and sodium hydrogencarbonate.
(b) Sodium hydrogencarbonate on reaction with hydrochloric acid gives sodium chloride, water and liberates carbon dioxide.
(c) Copper sulphate on treatment with potassium iodide precipitates cuprous iodide (Cu2I2), liberates iodine gas and also forms potassium sulphate.

06/11/2024

Science

10th